Bifidobacterium animalis subsp. lactis HN019 Effects on Gut Health: A Review

Abstract

Optimal gut motility is central to bowel function and gut health. The link between the gut dysmotility related disorders and dysfunctional-intestinal barriers has led to a hypothesis that certain probiotics could help in normalizing gut motility and maintain gut health. This review investigates the roles of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019™) on gut health, and its mechanisms of action in various pre-clinical and clinical studies. Research supports the hypothesis that B. lactis HN019™ has a beneficial role in maintaining intestinal barrier function during gastrointestinal infections by competing and excluding potential pathogens via different mechanisms; maintaining normal tight junction function in vitro; and regulating host immune defense toward pathogens in both in vitro and human studies. This has been observed to lead to reduced incidence of diarrhea. Interestingly, B. lactis HN019™ also supports normal physiological function in immunosenescent elderly and competes and excludes potential pathogens. Furthermore, B. lactis HN019™ reduced intestinal transit time and increased bowel movement frequency in functional constipation, potentially by modulating gut-brain-microbiota axis, mainly via serotonin signaling pathway, through short chain fatty acids derived from microbial fermentation. B. lactis HN019™ is thus a probiotic that can contribute to relieving gut dysmotility related disorders.

Keywords: Bifidobacterium animalis subsp. lactis HN019; bowel function; diarrhea; gut motility; gut–brain; intestinal barrier; probiotic.

Figure 1

Potential mechanisms how Bifidobacterium lactis HN019™ (HN019) may modulate colonic motility in humans. The human intestinal epithelial cell layer comprises, among others, of epithelial cells (EC) and enterochromaffin cells (ECM) lining the gut wall. B. lactis HN019™ may stimulate Lactobacilli and Bifidobacteria and inhibit certain Gram-negative bacteria (G⁻ bacteria). Bacteria-derived and neurotransmitters or modulators of dietary origin, such as deconjugated bile acids (dBA), short chain fatty acids (SCFA), and serotonin (5-HT) could interact with their host receptors expressed in the epithelial cell layer; G protein-coupled receptors (GPR); and 5-HT receptors (5-HT R). Microvesicles (MV), peptidoglycan (PG), and lipopolysaccharide (LPS) from different bacteria interact with Toll-like receptors (TLRs). These components may also cross the epithelial layer and like the receptors signal afferent neurons in the enteric nervous system (ENS) with among others acetylcholine (ACh) to regulate colonic motility. Modified after Dalziel et al. (2021) (with permission). ©Pinja Kettunen/SciArt and IFF, with permission.