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In recent years, bifidobacterial populations in the gut of various monkey species have been assessed in several ecological surveys, unveiling a diverse, yet unexplored ecosystem harbouring novel species. In the current study, we investigated the species distribution of bifidobacteria present in 23 different species of primates, including human samples, by means of 16S rRNA microbial profiling and internal transcribed spacer bifidobacterial profiling. Based on the observed bifidobacterial‐host co‐phylogeny, we found a statistically significant correlation between the Hominidae family and particular bifidobacterial species isolated from humans, indicating phylosymbiosis between these lineages. Furthermore, phylogenetic and glycobiome analyses, based on 40 bifidobacterial species isolated from primates, revealed that members of the Bifidobacterium tissieri phylogenetic group, which are typical gut inhabitants of members of the Cebidae family, descend from an ancient ancestor with respect to other bifidobacterial taxa isolated from primates.

[Background] Some patients complain that eating lettuce, gives them gas and abdominal distention. Our aim was to determine to what extent the patients' assertion is sustained by evidence. [Methods] An in vitro study measured the amount of gas produced during the process of fermentation by a preparation of human colonic microbiota (n = 3) of predigested lettuce, as compared to beans, a high gas-releasing substrate, to meat, a low gas-releasing substrate, and to a nutrient-free negative control. A clinical study in patients complaining of abdominal distention after eating lettuce (n = 12) measured the amount of intestinal gas and the morphometric configuration of the abdominal cavity in abdominal CT scans during an episode of lettuce-induced distension as compared to basal conditions. [Key Results] Gas production by microbiota fermentation of lettuce in vitro was similar to that of meat (P =.44), lower than that of beans (by 78 ± 15%; P <.001) and higher than with the nutrient-free control (by 25 ± 19%; P =.05). Patients complaining of abdominal distension after eating lettuce exhibited an increase in girth (35 ± 3 mm larger than basal; P <.001) without significant increase in colonic gas content (39 ± 4 mL increase; P =.071); abdominal distension was related to a descent of the diaphragm (by 7 ± 3 mm; P =.027) with redistribution of normal abdominal contents. [Conclusion and Inferences] Lettuce is a low gas-releasing substrate for microbiota fermentation and lettuce-induced abdominal distension is produced by an uncoordinated activity of the abdominal walls. Correction of the somatic response might be more effective than the current dietary restriction strategy.

Background: There is increasing evidence of the key role that the gut microbiota plays in inflammatory diseases. Objectives: To identify differences in the faecal microbial composition of patients with psoriasis compared with healthy individuals in order to unravel the microbiota profiling in this autoimmune disease. Methods: 16S rRNA gene sequencing and bioinformatic analyses were performed with the total DNA extracted from the faecal microbiota of 19 patients with psoriasis and 20 healthy individuals from the same geographic location. Results: Gut microbiota composition of patients with psoriasis displayed a lower diversity and different relative abundance of certain bacterial taxa compared with healthy individuals. Conclusions: The gut microbiota profile of patients with psoriasis displayed a clear dysbiosis that can be targeted for microbiome-based therapeutic approaches.

The gastrointestinal tract of mammals hosts a high and diverse number of different microorganisms, known as intestinal microbiota. Many probiotics were originally isolated from the gastrointestinal tract, and they were defined by the Food and Agriculture Organization of the United Nations (FAO)/WHO as “live microorganisms which when administered in adequate amounts confer a health benefit on the host.” Probiotics exert their beneficial effects on the host through four main mechanisms: interference with potential pathogens, improvement of barrier function, immunomodulation and production of neurotransmitters, and their host targets vary from the resident microbiota to cellular components of the gut–brain axis. However, in spite of the wide array of beneficial mechanisms deployed by probiotic bacteria, relatively few effects have been supported by clinical data. In this regard, different probiotic strains have been effective in antibiotic‐associated diarrhea or inflammatory bowel disease for instance. The aim of this review was to compile the molecular mechanisms underlying the beneficial effects of probiotics, mainly through their interaction with the intestinal microbiota and with the intestinal mucosa. The specific benefits discussed in this paper include among others those elicited directly through dietary modulation of the human gut microbiota.