PhD, MRes, BSc Hons
Fermented food contains bacteria to proliferate bacterial growth in the gut microbiome
In 10 seconds? Do you have a gut feeling for foods which are good for you? Fermented food improves the level of good bacteria in our gut microbiome. The byproducts of these have been shown to have a huge impact on our health.
Why is bacteria important? Our intestines are home to billions of species of bacteria called the gut microbiome. To name a few, you may have heard of lactobacilli, Bifidobacteria and Bacteriodes. The bacteria entering our gut proliferates and makes more bacteria. The more good bacteria we have in our gut, the better. The gut microbiome communicates with our immune system. It tells it to attack disease causing invaders, while being gentle enough so that it doesn’t attack our body.
Don’t believe it? Scientists at Harvard Medical school have listened to crosstalk between gut bacteria and immune cells. Gut bacteria boosted the activity of immune cells, while others reduced the activity. Bacteria can turn on and off certain genes in the intestines. Professor Dennis Kasper said bacteria can be used as a therapeutic to fine-tune certain immune responses in the future.
What are the health benefits of fermented foods? If we eat fermented food every day we will maintain the right amount of good bacteria in our gut. Scientists say this may diminish allergies. A population study found that communities of people who eat a lot of fermented food have lower rates of allergies and asthma.
People who have rheumatoid arthritis have low levels of Bifidbacterium and Bacteroides in their gut. In an animal study, arthritic mice had the good bacteria removed from their gut and this resulted in worse arthritic symptoms. This shows that it is important for those with arthritis to have good bacteria in the gut microbiome.
When fibre is fermented in your gut, it produces short chain fatty acids. Inflammatory bowel disease patients have low concentrations of short chain fatty acids in their microbiome. Consequently, symptoms improve once short chain fatty acid levels increase. To support this, research shows that populations who eat a lot of dietary fibre have a low incidence of colitis, type 2 diabetes and colon cancer.
Abstract: Probiotics are usually defined as microbial food supplements with beneficial effects on the consumers. Most probiotics fall into the group of organisms' known as lactic acid-producing bacteria and are normally consumed in the form of yogurt, fermented milks or other fermented foods. Some of the beneficial effect of lactic acid bacteria consumption include: (i) improving intestinal tract health; (ii) enhancing the immune system, synthesizing and enhancing the bioavailability of nutrients; (iii) reducing symptoms of lactose intolerance, decreasing the prevalence of allergy in susceptible individuals; and (iv) reducing risk of certain cancers. The mechanisms by which probiotics exert their effects are largely unknown, but may involve modifying gut pH, antagonizing pathogens through production of antimicrobial compounds, competing for pathogen binding and receptor sites as well as for available nutrients and growth factors, stimulating immunomodulatory cells, and producing lactase. Selection criteria, efficacy, food and supplement sources and safety issues around probiotics are reviewed. Recent scientific investigation has supported the important role of probiotics as a part of a healthy diet for human as well as for animals and may be an avenue to provide a safe, cost effective, and 'natural' approach that adds a barrier against microbial infection. This paper presents a review of probiotics in health maintenance and disease prevention.
Pub.: 16 May '06, Pinned: 05 May '17
Abstract: Recent studies have suggested that the intestinal microbiome plays an important role in modulating risk of several chronic diseases, including inflammatory bowel disease, obesity, type 2 diabetes, cardiovascular disease, and cancer. At the same time, it is now understood that diet plays a significant role in shaping the microbiome, with experiments showing that dietary alterations can induce large, temporary microbial shifts within 24 h. Given this association, there may be significant therapeutic utility in altering microbial composition through diet. This review systematically evaluates current data regarding the effects of several common dietary components on intestinal microbiota. We show that consumption of particular types of food produces predictable shifts in existing host bacterial genera. Furthermore, the identity of these bacteria affects host immune and metabolic parameters, with broad implications for human health. Familiarity with these associations will be of tremendous use to the practitioner as well as the patient.
Pub.: 09 Apr '17, Pinned: 05 May '17
Abstract: Over the past decade, application of culture-independent, next generation DNA sequencing has dramatically enhanced our understanding of the composition of the gut microbiome and its association with human states of health and disease. Host genetics, age, and environmental factors such as where and who you live with, use of pre-, pro- and antibiotics, exercise and diet influence the short- and long-term composition of the microbiome. Dietary intake is a key determinant of microbiome composition and diversity and studies to date have linked long-term dietary patterns as well as short-term dietary interventions to the composition and diversity of the gut microbiome. The goal of this special focus issue was to review the role of diet in regulating the composition and function of the gut microbiota across the lifespan, from pregnancy to old age. Overall dietary patterns, as well as perturbations such as undernutrition and obesity, as well as the effects of dietary fiber/prebiotics and fat composition are explored.
Pub.: 11 Mar '17, Pinned: 05 May '17
Abstract: Understanding how the human gut microbiota and host are affected by probiotic bacterial strains requires carefully controlled studies in humans and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks before, 7 weeks during, and 4 weeks after consumption of a commercially available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied before and after gavage with all five sequenced FMP strains. No significant changes in bacterial species composition or in the proportional representation of genes encoding known enzymes were observed in the feces of humans consuming the FMP. Only minimal changes in microbiota configuration were noted in mice after single or repeated gavage with the FMP consortium. However, RNA-Seq analysis of fecal samples and follow-up mass spectrometry of urinary metabolites disclosed that introducing the FMP strains into mice results in significant changes in expression of microbiome-encoded enzymes involved in numerous metabolic pathways, most prominently those related to carbohydrate metabolism. B. animalis subsp. lactis, the dominant persistent member of the FMP consortium in gnotobiotic mice, up-regulates a locus in vivo that is involved in the catabolism of xylooligosaccharides, a class of glycans widely distributed in fruits, vegetables, and other foods, underscoring the importance of these sugars to this bacterial species. The human fecal metatranscriptome exhibited significant changes, confined to the period of FMP consumption, that mirror changes in gnotobiotic mice, including those related to plant polysaccharide metabolism. These experiments illustrate a translational research pipeline for characterizing the effects of FMPs on the human gut microbiome.
Pub.: 28 Oct '11, Pinned: 04 May '17
Abstract: Obesity is a metabolic disorder afflicting people globally. There has been a pivotal advancement in the understanding of the intestinal microbiota composition and its implication in extraintestinal (metabolic) diseases. Therefore, any agent modulating gut microbiota may produce an influential effect in preventing the pathogenesis of disease. Probiotics are live microbes that, when administered in adequate amounts, have been shown to confer health benefits to the host. Over the years, probiotics have been a part of the human diet in the form of different fermented foods consumed around the world. Their influence on different physiologic functions in the host is increasingly being documented. The antiobesity potential of probiotics is also gaining wide attention because of increasing evidence of the role of gut microbiota in energy homeostasis and fat accumulation. Probiotics have also been shown to interact with the resident bacterial members already present in the gut by altering their properties, which may also affect the metabolic pathways involved in the regulation of fat metabolism. The underlying pathways governing the antiobesity effects of probiotics remain unclear. However, it is hoped that the evidence presented and discussed in this review will encourage and thus drive more extensive research in this field.
Pub.: 05 Jan '13, Pinned: 04 May '17
Abstract: The microbial community populating the human digestive tract has been linked to the development of obesity, diabetes and liver diseases. Proposed mechanisms on how the gut microbiota could contribute to obesity and metabolic diseases include: (1) improved energy extraction from diet by the conversion of dietary fibre to SCFA; (2) increased intestinal permeability for bacterial lipopolysaccharides (LPS) in response to the consumption of high-fat diets resulting in an elevated systemic LPS level and low-grade inflammation. Animal studies indicate differences in the physiologic effects of fermentable and non-fermentable dietary fibres as well as differences in long- and short-term effects of fermentable dietary fibre. The human intestinal microbiome is enriched in genes involved in the degradation of indigestible polysaccharides. The extent to which dietary fibres are fermented and in which molar ratio SCFA are formed depends on their physicochemical properties and on the individual microbiome. Acetate and propionate play an important role in lipid and glucose metabolism. Acetate serves as a substrate for de novo lipogenesis in liver, whereas propionate can be utilised for gluconeogenesis. The conversion of fermentable dietary fibre to SCFA provides additional energy to the host which could promote obesity. However, epidemiologic studies indicate that diets rich in fibre rather prevent than promote obesity development. This may be due to the fact that SCFA are also ligands of free fatty acid receptors (FFAR). Activation of FFAR leads to an increased expression and secretion of enteroendocrine hormones such as glucagon-like-peptide 1 or peptide YY which cause satiety. In conclusion, the role of SCFA in host energy balance needs to be re-evaluated.
Pub.: 19 Dec '14, Pinned: 04 May '17
Abstract: The purposeful application of fermentation in food and beverage preparation, as a means to provide palatability, nutritional value, preservative, and medicinal properties, is an ancient practice. Fermented foods and beverages continue to make a significant contribution to the overall patterns of traditional dietary practices. As our knowledge of the human microbiome increases, including its connection to mental health (for example, anxiety and depression), it is becoming increasingly clear that there are untold connections between our resident microbes and many aspects of physiology. Of relevance to this research are new findings concerning the ways in which fermentation alters dietary items pre-consumption, and in turn, the ways in which fermentation-enriched chemicals (for example, lactoferrin, bioactive peptides) and newly formed phytochemicals (for example, unique flavonoids) may act upon our own intestinal microbiota profile. Here, we argue that the consumption of fermented foods may be particularly relevant to the emerging research linking traditional dietary practices and positive mental health. The extent to which traditional dietary items may mitigate inflammation and oxidative stress may be controlled, at least to some degree, by microbiota. It is our contention that properly controlled fermentation may often amplify the specific nutrient and phytochemical content of foods, the ultimate value of which may associated with mental health; furthermore, we also argue that the microbes (for example, Lactobacillus and Bifidobacteria species) associated with fermented foods may also influence brain health via direct and indirect pathways.
Pub.: 15 Jan '14, Pinned: 04 May '17
Abstract: With depressive disorders the leading source of disability globally, the identification of new targets for prevention and management is imperative. A rapidly emerging field of research suggests that the microbiome-gut-brain axis is of substantial relevance to mood and behaviour. Similarly, unhealthy diet has recently emerged as a significant correlate of and risk factor for depression. This review provides evidence for the gut microbiota as a key factor mediating the link between diet and depressive illness.The development of new technologies is affording a better understanding of how diet influences gut microbiota composition and activity and how this may, in turn, influence depressive illness. New interventions are also suggesting the possible utility of pre and probiotic formulations and fermented food in influencing mental health.Although in its early stages, the emerging field of research focused on the human microbiome suggests an important role for the gut microbiota in influencing brain development, behaviour and mood in humans. The recognition that the gut microbiota interacts bidirectionally with other environmental risk factors, such as diet and stress, suggests promise in the development of interventions targeting the gut microbiota for the prevention and treatment of common mental health disorders.
Pub.: 22 Nov '14, Pinned: 04 May '17
Abstract: Rapid environmental transition and modern lifestyles are likely driving changes in the biodiversity of the human gut microbiota. With clear effects on physiologic, immunologic, and metabolic processes in human health, aberrations in the gut microbiome and intestinal homeostasis have the capacity for multisystem effects. Changes in microbial composition are implicated in the increasing propensity for a broad range of inflammatory diseases, such as allergic disease, asthma, inflammatory bowel disease (IBD), obesity, and associated noncommunicable diseases (NCDs). There are also suggestive implications for neurodevelopment and mental health. These diverse multisystem influences have sparked interest in strategies that might favorably modulate the gut microbiota to reduce the risk of many NCDs. For example, specific prebiotics promote favorable intestinal colonization, and their fermented products have anti-inflammatory properties. Specific probiotics also have immunomodulatory and metabolic effects. However, when evaluated in clinical trials, the effects are variable, preliminary, or limited in magnitude. Fecal microbiota transplantation is another emerging therapy that regulates inflammation in experimental models. In human subjects it has been successfully used in cases of Clostridium difficile infection and IBD, although controlled trials are lacking for IBD. Here we discuss relationships between gut colonization and inflammatory NCDs and gut microbiota modulation strategies for their treatment and prevention.
Pub.: 09 Jan '15, Pinned: 04 May '17
Abstract: The infant gut is rapidly colonized by microorganisms soon after birth, and the composition of the microbiota is dynamic in the first year of life. Although a stable microbiome may not be established until 1 to 3 years after birth, the infant gut microbiota appears to be an important predictor of health outcomes in later life.We obtained stool at one year of age from 173 white Caucasian and 182 South Asian infants from two Canadian birth cohorts to gain insight into how maternal and early infancy exposures influence the development of the gut microbiota. We investigated whether the infant gut microbiota differed by ethnicity (referring to groups of people who have certain racial, cultural, religious, or other traits in common) and by breastfeeding status, while accounting for variations in maternal and infant exposures (such as maternal antibiotic use, gestational diabetes, vegetarianism, infant milk diet, time of introduction of solid food, infant birth weight, and weight gain in the first year).We demonstrate that ethnicity and infant feeding practices independently influence the infant gut microbiome at 1 year, and that ethnic differences can be mapped to alpha diversity as well as a higher abundance of lactic acid bacteria in South Asians and a higher abundance of genera within the order Clostridiales in white Caucasians.The infant gut microbiome is influenced by ethnicity and breastfeeding in the first year of life. Ethnic differences in the gut microbiome may reflect maternal/infant dietary differences and whether these differences are associated with future cardiometabolic outcomes can only be determined after prospective follow-up.
Pub.: 31 Mar '17, Pinned: 04 May '17
Abstract: The gut microbiota (GM) consists of resident commensals and transient microbes conveyed by the diet but little is known about the role of the latter on GM homeostasis. Here we show, by a conjunction of quantitative metagenomics, in silico genome reconstruction and metabolic modeling, that consumption of a fermented milk product containing dairy starters and Bifidobacterium animalis potentiates colonic short chain fatty acids production and decreases abundance of a pathobiont Bilophila wadsworthia compared to a milk product in subjects with irritable bowel syndrome (IBS, n = 28). The GM changes parallel improvement of IBS state, suggesting a role of the fermented milk bacteria in gut homeostasis. Our data challenge the view that microbes ingested with food have little impact on the human GM functioning and rather provide support for beneficial health effects.
Pub.: 12 Sep '14, Pinned: 04 May '17
Abstract: The study reports the growth, acidification and proteolysis of eight selected lactic acid bacteria in skim and soy milk. Angiotensin-converting enzyme inhibition and antimicrobial profiles of skim and soy milk fermented by the lactic acid bacteria were also determined. Among eight lactic cultures (S. thermophilus MD2, L. helveticus V3, L. rhamnosus NS6, L. rhamnosus NS4, L. bulgaricus NCDC 09, L. acidophilus NCDC 15, L. acidophilus NCDC 298 and L. helveticus NCDC 292) studied, L. bulgaricus NCDC 09 and S. thermophilus MD2 decreased the pH of skim and soy milk in greater extent. Acid production (i.e. titratable acidity) by L. bulgaricus NCDC 09 and L. helveticus V3 was higher than other strains. Higher viable counts were observed in S. thermophilus MD2 and L. helveticus V3. Higher proteolysis was exhibited by S. thermophilus MD2 and L. rhamnosus NS6 in both skim and soy milk. Milk fermented by S. thermophilus (MD2) exhibited highest angiotensin-converting enzyme inhibition. Antimicrobial activities of cell-free supernatant of milk fermented by S. thermophilus MD2 and L. helveticus V3 were higher. All the tested lactic acid bacteria performed better in skim milk as compared to soy milk.
Pub.: 30 Apr '17, Pinned: 03 May '17
Abstract: Lactic acid bacteria (LAB) form a major component of gut microbiota and are often used as probiotics for fermented foods, such as yoghurt. In this study, we aimed to evaluate immunomodulatory activity of LAB, especially that of Lactobacillus bulgaricus ME-552 (ME552) and Streptococcus thermophilus ME-553 (ME553). In vivo/in vitro assay was performed in order to investigate their effects on T cell function. After oral administration of ME553 to C57BL/6 mice, the amount of both interferon γ (IFN-γ) and interleukin 17 (IL-17) produced by cluster of differentiation (CD) 4+ T cells from Peyer’s patches (PPs) were significantly enhanced. On the other hand, ME552 only up-regulated the production of IL-17 from PP cells. The extent of induction for IFN-γ production differed between ME552 and ME553. These results suggest that LAB modulate T cell effector functions and mucosal immunity.
Pub.: 23 Dec '16, Pinned: 03 May '17
Abstract: Chinese traditional fermented foods have a very long history dating back thousands of years and have become an indispensable part of Chinese dietary culture. A plethora of research has been conducted to unravel the composition and dynamics of microbial consortia associated with Chinese traditional fermented foods using culture-dependent as well as culture-independent methods, like different high-throughput sequencing (HTS) techniques. These HTS techniques enable us to understand the relationship between a food product and its microbes to a greater extent than ever before. Considering the importance of Chinese traditional fermented products, the objective of this paper is to review the diversity and dynamics of microbiota in Chinese traditional fermented foods revealed by HTS approaches.
Pub.: 06 Apr '17, Pinned: 03 May '17
Abstract: Endogenous and exogenous signals derived by the gut microbiota such as lipopolysaccharides (LPS) orchestrate inflammatory responses contributing to development of the endothelial dysfunction associated with atherosclerosis in obesity, metabolic syndrome, and diabetes. Endothelial progenitor cells (EPCs), bone marrow derived stem cells, promote recovery of damaged endothelium playing a pivotal role in cardiovascular repair. Since healthy nutrition improves EPCs functions, we evaluated the effect of a fermented grain, Lisosan G (LG), on early EPCs exposed to LPS. The potential protective effect of LG against LPS-induced alterations was evaluated as cell viability, adhesiveness, ROS production, gene expression, and NF-kB signaling pathway activation. Our results showed that LPS treatment did not affect EPCs viability and adhesiveness but induced endothelial alterations via activation of NF-kB signaling. LG protects EPCs from inflammation as well as from LPS-induced oxidative and endoplasmic reticulum (ER) stress reducing ROS levels, downregulating proinflammatory and proapoptotic factors, and strengthening antioxidant defense. Moreover, LG pretreatment prevented NF-kB translocation from the cytoplasm into the nucleus caused by LPS exposure. In human EPCs, LPS increases ROS and upregulates proinflammatory tone, proapoptotic factors, and antioxidants. LG protects EPCs exposed to LPS reducing ROS, downregulating proinflammatory and proapoptotic factors, and strengthening antioxidant defenses possibly by inhibiting NF-κB nuclear translocation.
Pub.: 08 Apr '17, Pinned: 03 May '17
Abstract: Red ginseng is a well-known alternative medicine with anti-inflammatory activity. It exerts pharmacological effects through the transformation of saponin into metabolites by intestinal microbiota. Given that intestinal microflora vary among individuals, the pharmacological effects of red ginseng likely vary among individuals. In order to produce homogeneously effective red ginseng, we prepared probiotic-fermented red ginseng and evaluated its activity using a dextran sulfate sodium (DSS)-induced colitis model in mice. Initial analysis of intestinal damage indicated that the administration of probiotic-fermented red ginseng significantly decreased the severity of colitis, compared with the control and the activity was higher than that induced by oral administration of ginseng powder or probiotics only. Subsequent analysis of the levels of serum IL-6 and TNF-α, inflammatory biomarkers that are increased at the initiation stage of colitis, were significantly decreased in probiotic-fermented red ginseng-treated groups in comparison to the control group. The levels of inflammatory cytokines and mRNAs for inflammatory factors in colorectal tissues were also significantly decreased in probiotic-fermented red ginseng-treated groups. Collectively, oral administration of probiotic-fermented red ginseng reduced the severity of colitis in a mouse model, suggesting that it can be used as a uniformly effective red ginseng product.
Pub.: 17 Apr '17, Pinned: 03 May '17
Abstract: Approximately 25 strains of lactobacilli isolated from different dairy products and fermented vegetables were screened according to their possibility to show the high auto-aggregation and co-aggregation. The strains Lactobacillus helveticus INRA-2010-H11, Lactobacillus rhamnosus INA-5.1, and Lactobacillus acidophilus JM-2012 were determined to have the high auto-aggregation (approximately 73, 46, and 70.5% correspondingly). A high co-aggregation capacity (75.53%) for strains INRA-2010-H11 and JM-2012 was shown. The adhesion degree of INRA-2010-H11 on the surface of buccal epithelial cells was 88.23%. The study of INRA-2010-H11, JM-2012, and both strains' mixture (1:1) adhesion capacity on the surface of epithelial HeLa cells revealed the adhesion of 1.1 × 10(6), 6.3 × 10(4), and 2.3 × 10(5) CFU, respectively, from starter amount of CFU 10(7) and 10(8) for both strains. In vivo experiments of LAB adhesion in gastrointestinal tract of mouse revealed the presence of 2.5 × 10(9), 1.2 × 10(9), and 1.5 × 10(9) CFU of LAB in control and groups of mouse, fed by INRA-2010-H11 and mixture, respectively. Feeding by investigated lactobacilli was suggested to lead to microbiota biodiversity reduction in small intestine and colon and its augmentation in stomach. Thus, INRA-2010-H11 demonstrated a high aggregation and adhesion activity so it has the potential as a good probiotic strain.
Pub.: 30 Apr '17, Pinned: 03 May '17
Abstract: Inflammatory bowel disease (IBD) is characterized by chronic or relapsing immune system activation and inflammation within the gastrointestinal tract. The lack of safety and efficacy of standard therapies, the use of food supplements for managing IBD is increasing, and many studies have reported that various food supplements provide many beneficial effects for the IBD.This study aimed to evaluate the anti-colitis effects of dietary supplementation with a fermented barley and soybean mixture (BS) on intestinal inflammation using a murine model of IBD. Female C57BL/6 mice were administered with either BS (100 and 200 mg/kg/day) or vehicle (PBS) control through oral gavages for 3 days and received 5% dextran sulfate sodium (DSS) drinking water to induce colitis. Mice body weight was measured every two days and disease activity index (DAI) score was determined on Day 15; mice were sacrificed and colons were analyzed by H & E staining and RT-PCR. We also measured intestinal barrier function in vitro using DSS-treated Caco-2 cells by assessing ZO-1 immunofluorescence staining and Western blotting and in vivo by measuring serum level of FITC-Dextran and by performing bacteria culture from mesenteric lymph nodes (MLN) extract. The gut microbiota was examined by real time PCR using fecal DNA.We found that BS alleviated the severity of colitis in a DSS-induced colitis mouse model, and suppressed levels of pro-inflammatory cytokines in colonic tissue. Moreover, BS prevented epithelial barrier dysfunction, inducing an increase of tight junction protein levels in colonic tissues, BS also inhibited FITC-dextran permeability, and suppressed bacterial translocation to MLNs. In addition, BS increased the levels of Lactobacilli and Bacteroides, which have anti-inflammatory properties.Our study suggests that BS has protective roles against inflammatory bowel disease through changes in inflammatory activity, tight junction protein expression, and gut microbiota composition in DSS-induced colitis.
Pub.: 04 Dec '16, Pinned: 24 Apr '17
Abstract: Many studies have been published lately verifying the probiotic character of kefir grains. Most of them focused on the benefits to human health through the consumption of fermented food with kefir grains. However, the challenge is to characterize and isolate specific probiotic microorganisms involved in the kefir microbiota. The main reason for this is that the food industry prefers to apply isolated probiotic microorganisms from kefir grains rather than kefir grains in order to produce respective fermented products with added value. Thus, modern molecular techniques such as polymerase chain reaction (PCR)-based amplification, new generation sequencing (NGS) or denaturing gradient gel electrophoresis (DGGE) analyses have been applied. Furthermore, this review emphasizes the latest outcomes regarding the health benefits of the consumption of foods fermented with kefir grains and particularly the isolation of microorganisms from kefir grains worldwide, some of them exhibiting probiotic properties.
Pub.: 23 Dec '16, Pinned: 24 Apr '17