Secretome of Intestinal Bacilli: A Natural Guard against Pathologies

Abstract

Current studies of human gut microbiome usually do not consider the special functional role of transient microbiota, although some of its members remain in the host for a long time and produce broad spectrum of biologically active substances. Getting into the gastrointestinal tract (GIT) with food, water and probiotic preparations, two representatives of Bacilli class, genera Bacillus and Lactobacillus, colonize epithelium blurring the boundaries between resident and transient microbiota. Despite their minor proportion in the microbiome composition, these bacteria can significantly affect both the intestinal microbiota and the entire body thanks to a wide range of secreted compounds. Recently, insufficiency and limitations of pure genome-based analysis of gut microbiota became known. Thus, the need for intense functional studies is evident. This review aims to characterize the Bacillus and Lactobacillus in GIT, as well as the functional roles of the components released by these members of microbial intestinal community. Complex of their secreted compounds is referred by us as the “bacillary secretome.” The composition of the bacillary secretome, its biological effects in GIT and role in counteraction to infectious diseases and oncological pathologies in human organism is the subject of the review.

The effects of the supplementation of multi‐strain probiotics on intestinal microbiota, metabolites and inflammation of young SPF chickens challenged with Salmonella enterica subsp. enterica

“…The intestinal microbiota can ferment complex polysaccharides and fiber into a range of terminal metabolites such as SCFAs with diverse effects on gut health. For instance, microbes in the Bacilli genera can generate SCFAs from dietary carbohydrates (Ilinskaya, Ulyanova, Yarullina, & Gataullin, ). In the present study, the increased presence of the Bacilli genera might have contributed to the higher concentration of total volatile fatty acids, acetic acid, and butyric acid in the ceca of the ProSal group.…”

“…A low intestinal pH creates an environment that is favorable to beneficial intestinal microbes and is unsuitable for many other bacteria (Nyangale et al., ). The multifaceted roles of SCFAs make them the key molecular link between diet, the microbiome, and health (Ilinskaya et al., ).…”

Analyzing the Secretome of Gut Microbiota as the Next Strategy For Early Detection of Colorectal Cancer

“…The crosstalk between microbiota and host is reckoned intricate . Both human gut and microbiota generate abundance of proteins and metabolites which influence the host's physiology and behavior, participate in cancer development and regulate various metabolic pathways .…”

“…Both human gut and microbiota generate abundance of proteins and metabolites which influence the host's physiology and behavior, participate in cancer development and regulate various metabolic pathways . These biomolecules include antibiotics, enzymes, vitamins, amino acids, minerals, energy metabolites, short chain fatty acids (SCFAs), neurotransmitters, hormones, microbial antigens, pathogen‐associated molecular patterns (PAMPs), and toxins, which are “connected” to various organs namely lungs, brain, liver, and muscle via host's circulation . Studies have prevailed on the capability of the host to modulate gut microbial community, for instance, by producing α‐defensins, an antimicrobial peptide responsible to eliminate pathogens and maintain gut homeostasis .…”

“…The production of immunoglobulin A (IgA) by the hosts helps to maintain gut commensal microbiota, along with the synthesis of microRNA (miRNA) proven to be vital in regulating microbial growth and transcript. Apart from that, the genetic makeup of the host has also played a role in controlling metabolites production of the microbes …”