I am a scientist specialized in mitochondria and genetics, but above all, I am just curious guy who loves learning new things.


Having trouble with your roomies?

In 10 seconds? Most of the cells in our body are not human but bacteria and recent studies show that these little fellows are essential for our health and well being, influencing our immune system, metabolism, neurodevelopment and behavior.

Where in our body do these roommates live? Most of the bacteria in our microbiota are found in the colon, where they create symbiotic host-bacterial interactions that are fundamental for our health, specially for our immune system, helping us recognize between harmful and helpful microbes, and for the structure and function of our brain, thanks to a bidirectional relationship between the brain and the microbiota in our gut.

And how do microbes in my gut affect my brain? The bacteria in our gastrointestinal tract communicate with our cells and thereby modulate the expression of cytokines, molecular messengers that can travel around our body, delivering signals from our gut to our brain. The dysregulation of this cytokine signaling, caused by an alteration on the composition and diversity of our gut microbiota, has been shown to affect brain function, with consequences on emotional and cognitive development, mood and social behavior, making us irritable and less altruistic. And this can even lead to neuropsychiatric disorders, such as anxiety and depression.

What kind of changes can affect the gut microbiota? Several aspects of our modern life can altere our microbiota, such as stress, diet, alcohol abuse and overuse of antibiotics, which not only eliminate harmful microbes but also helpful and necessary bacteria.

And how can we avoid these alterations? In addition to living a less stressful life with a better diet, and avoiding excessive use of antibiotics, we can also positively modulate our microbiota by using prebiotics and probiotics, which could have antidepressant and antipsychotic effects by normalizing the gut microbial population.


Brain structure and response to emotional stimuli as related to gut microbial profiles in healthy women.

Abstract: Brain-gut-microbiota interactions may play an important role in human health and behavior. However, while rodent models have demonstrated effects of the gut microbiota on emotional, nociceptive and social behaviors, there is little translational human evidence to date. In this study we identify brain and behavioral characteristics of healthy women clustered by gut microbiota profiles.Forty women supplied fecal samples for 16s rRNA profiling. Microbial clusters were identified using Partitioning Around Medoids. Functional magnetic resonance imaging was acquired. Microbiota-based group differences were analyzed in response to affective images. Structural and diffusion tensor imaging provided gray matter metrics (volume, cortical thickness, mean curvature, surface area) as well as fiber density between regions. A sparse Partial Least Square-Discrimination Analysis was applied to discriminate microbiota-clusters using white and gray matter metrics.Two bacterial genus-based clusters were identified, one with greater Bacteroides abundance (n=33), one with greater Prevotella abundance (n=7). The Prevotella group showed less hippocampal activity viewing negative valences images. White and gray matter imaging discriminated the two clusters, with accuracy of 66.7% and 87.2% respectively. The Prevotella cluster was associated with differences in emotional, attentional, and sensory processing regions. For gray matter, the Bacteroides cluster showed greater prominence in the cerebellum, frontal regions, and the hippocampus.These results support the concept of brain-gut-microbiota interactions in healthy humans. Further examination of the interaction between gut microbes, brain and affect in humans is needed to inform preclinical reports that microbial modulation may affect mood and behavior.

Pub.: 01 Jul '17, Pinned: 14 Sep '17

The microbiota-gut-brain axis as a key regulator of neural function and the stress response: Implications for human and animal health.

Abstract: The brain-gut-microbiota axis comprises an extensive communication network between the brain, the gut, and the microbiota residing there. Development of a diverse gut microbiota is vital for multiple features of behavior and physiology, as well as many fundamental aspects of brain structure and function. Appropriate early-life assembly of the gut microbiota is also believed to play a role in subsequent emotional and cognitive development. If the composition, diversity, or assembly of the gut microbiota is impaired, this impairment can have a negative impact on host health and lead to disorders such as obesity, diabetes, inflammatory diseases, and even potentially neuropsychiatric illnesses, including anxiety and depression. Therefore, much research effort in recent years has focused on understanding the potential of targeting the intestinal microbiota to prevent and treat such disorders. This review aims to explore the influence of the gut microbiota on host neural function and behavior, particularly those of relevance to stress-related disorders. The involvement of microbiota in diverse neural functions such as myelination, microglia function, neuronal morphology, and blood-brain barrier integrity across the life span, from early life to adolescence to old age, will also be discussed. Nurturing an optimal gut microbiome may also prove beneficial in animal science as a means to manage stressful situations and to increase productivity of farm animals. The implications of these observations are manifold, and researchers are hopeful that this promising body of preclinical work can be successfully translated to the clinic and beyond.

Pub.: 21 Jul '17, Pinned: 14 Sep '17

Gut microbiome composition is associated with temperament during early childhood.

Abstract: Understanding the dynamics of the gut-brain axis has clinical implications for physical and mental health conditions, including obesity and anxiety. As such disorders have early life antecedents, it is of value to determine if associations between the gut microbiome and behavior are present in early life in humans.We used next generation pyrosequencing to examine associations between the community structure of the gut microbiome and maternal ratings of child temperament in 77 children at 18-27months of age. It was hypothesized that children would differ in their gut microbial structure, as indicated by measures of alpha and beta diversity, based on their temperamental characteristics.Among both boys and girls, greater Surgency/Extraversion was associated greater phylogenetic diversity. In addition, among boys only, subscales loading on this composite scale were associated with differences in phylogenetic diversity, the Shannon Diversity index (SDI), beta diversity, and differences in abundances of Dialister, Rikenellaceae, Ruminococcaceae, and Parabacteroides. In girls only, higher Effortful Control was associated with a lower SDI score and differences in both beta diversity and Rikenellaceae were observed in relation to Fear. Some differences in dietary patterns were observed in relation to temperament, but these did not account for the observed differences in the microbiome.Differences in gut microbiome composition, including alpha diversity, beta diversity, and abundances of specific bacterial species, were observed in association with temperament in toddlers. This study was cross-sectional and observational and, therefore, does not permit determination of the causal direction of effects. However, if bidirectional brain-gut relationships are present in humans in early life, this may represent an opportunity for intervention relevant to physical as well as mental health disorders.

Pub.: 03 Dec '14, Pinned: 14 Sep '17