The Potential of Gut Commensals in Reinforcing Intestinal Barrier Function and Alleviating Inflammation

Abstract

The intestinal microbiota, composed of pro- and anti-inflammatory microbes, has an essential role in maintaining gut homeostasis and functionality. An overly hygienic lifestyle, consumption of processed and fiber-poor foods, or antibiotics are major factors modulating the microbiota and possibly leading to longstanding dysbiosis. Dysbiotic microbiota is characterized to have altered composition, reduced diversity and stability, as well as increased levels of lipopolysaccharide-containing, proinflammatory bacteria. Specific commensal species as novel probiotics, so-called next-generation probiotics, could restore the intestinal health by means of attenuating inflammation and strengthening the epithelial barrier. In this review we summarize the latest findings considering the beneficial effects of the promising commensals across all major intestinal phyla. These include the already well-known bifidobacteria, which use extracellular structures or secreted substances to promote intestinal health. Faecalibacterium prausnitzii, Roseburia intestinalis, and Eubacterium hallii metabolize dietary fibers as major short-chain fatty acid producers providing energy sources for enterocytes and achieving anti-inflammatory effects in the gut. Akkermansia muciniphila exerts beneficial action in metabolic diseases and fortifies the barrier function. The health-promoting effects of Bacteroides species are relatively recently discovered with the findings of excreted immunomodulatory molecules. These promising, unconventional probiotics could be a part of biotherapeutic strategies in the future.

The eradication of Helicobacter pylori restores rather than disturbs the gastrointestinal microbiota in asymptomatic young adults

“…Additionally, Alistipes has been identified as one of the top ten most abundant genera associated with human colorectal carcinoma, and it has been demonstrated to potently induce inflammation and tumorigenesis . Previous studies have shown that the Lachnoclostridium , Blautia, and Eubacterium hallii genera can produce short‐chain fatty acids (SCFAs) through the fermentation of soluble fiber . SCFAs have been shown to play a protective role in chronic diseases that involve the regulation of intestinal immune function, as well as in the maintenance of gut barrier .…”

“…35 Previous studies have shown that the Lachnoclostridium, Blautia, and Eubacterium hallii genera can produce short-chain fatty acids (SCFAs) through the fermentation of soluble fiber. 36,37 SCFAs have been shown to play a protective role in chronic diseases that involve the regulation of intestinal immune function, as well as in the maintenance of gut barrier. 38 The effect of antibiotics on gut microbiota has long been a concern in the implementation of H pylori eradication.…”

The microgenderome revealed: sex differences in bidirectional interactions between the microbiota, hormones, immunity and disease susceptibility

“…This occurs via microbiota effects on both innate and adaptive immunity (Table 1; Fig. 1) [2–12, 15–29]. The microbiota differs depending on the region of the GIT (oesophagus, stomach, upper and lower intestine, colon), but this review will focus on the colonic microbiota where an estimated 70% of the GIT microbiota reside [4].…”

Leaky gut: mechanisms, measurement and clinical implications in humans

“…There is also hope that probiotics or commensal organisms improve intestinal barrier function66; however, the evidence to date is sparse, often based on animal models rather than human studies, the beneficial effect may be through the effects of butyrate and the documented effects have been reported for the organism Akkermansia municiphila 67. There is a microintegral membrane protein (MIMP) that is the smallest domain of surface layer protein from Lactobacillus plantarum .…”