Milk digesta and milk protein fractions influence the adherence of Lactobacillus gasseri R and Lactobacillus casei FMP to human cultured cells

Abstract

Adhesion to the intestinal epithelium is considered an important feature of probiotic bacteria, which may increase their persistence in the intestine, allowing them to exert their beneficial health effect or promote the colonisation process. However, this feature might be largely dependent on the host specificity or diet. In the present study, we investigated the effect of selected milks and milk protein fractions on the ability of selected lactobacilli to adhere to the cells of an intestinal model based on co-culture Caco-2/HT29-MTX cell lines. Most milk digesta did not significantly affect bacterial adhesion except for UHT-treated milk and sheep milk. The presence of UHT-treated milk digesta reduced the adhesion of Lactobacillus gasseri R by 61% but not that of Lactobacillus casei FMP. However, sheep milk significantly increased the adherence of L. casei FMP (P < 0.05) but not of L. gasseri R. Among the protein fractions, rennet casein (RCN) and bovine serum albumin (BSA) showed reproducible patterns and strain-specific effects on bacterial adherence. While RCN reduced the adherence of L. gasseri R to <50% compared to the control, it did not have a significant effect on L. casei FMP. In contrast, BSA reduced L. casei FMP adherence to a higher extent than that of L. gasseri R. Whey protein (WH) tended to increase the adherence of both strains by 130%-180%. Recently, interactions between the host diet and its microbiota have attracted considerable interest. Our results may explain one of the aspects of the role of milk in the development of microbiota or support of probiotic supplements. Based on our data, we conclude that the persistence of probiotic strains supplemented as part of dairy food or constitutional microbiota in the gut might be affected negatively or positively by the food matrix through complex strain or concentration dependent effects.

Invited review: Dairy proteins and bioactive peptides: Modeling digestion and the intestinal barrier

“…Basiricò et al (2015) studied the release of ACE inhibitor peptides during in vitro gastrointestinal digestion of Parmigiano Reggiano cheese and their absorption through an in vitro model of intestinal epithelium. Volstatova et al (2016) combined the application of the INFOGEST protocol to study the effect of milk digesta from bovine, goats, and sheep on Lactobacillus adherence to human Caco-2/HT29-MTX intestinal cells. Pepe et al (2016) was the first to couple the in vitro digestion of Stracchino cheese to intestinal bioavailability and bioactivity studies.…”

In vitro-digested milk proteins: Evaluation of angiotensin-1-converting enzyme inhibitory and antioxidant activities, peptidomic profile, and mucin gene expression in HT29-MTX cells

“…Beta-casomorphin 7, a casein-derived peptide, exhibited an enhanced mucin gene expression mediated by opioid receptors in intestinal goblet cells (Zoghbi et al, 2006). To date, however, most attention has been focused on the bioactive effect of single peptides or hydrolysed proteins (Martínez-Maqueda et al, 2012a;Plaisaincié et al, 2015) with limited data on the effect of the whole pool of peptides obtained after in vitro digestion of milk proteins (Mukhopadhya et al, 2015;Volstatova et al, 2016), their potential mechanism of action and the candidate peptides involved. Casein and whey proteins, however, are present in milk and dairy products in their intact form and the total peptide pool produced from their digestion may have diverse effects in vivo.…”

Identification of Synbiotics Conducive to Probiotics Adherence to Intestinal Mucosa Using an In Vitro Caco-2 and HT29-MTX Cell Model

“…In addition, 3 -and 6 -sialyllactose, the two predominant oligosaccharides in human milk, enhance the adherence of B. infantis ATCC 15,697 [20]. The effects of different types of milk and milk protein fractions, such as albumin and casein, were also found to be substrate-and strain-specific against Lactobacillus gasseri and L. casei [21], with whole breast milk enhancing adherence in both strains. Notably, this differs from the consistent anti-adhesive effects observed in the present study, which utilized purified HMOs rather than whole milk.…”

“…Numerous studies have evaluated the microbial utilization of different oligosaccharides, especially focusing on their use as a carbon source for analyzing their growthpromoting effect and survival under GIT conditions. Bacterial adherence is linked to surface properties, which are, in turn, dependent on the structure and composition of the cell wall [21]. Accordingly, the anti-adhesive activity of most oligosaccharides is attributed to their ability to mimic cell receptors that bind pathogens, thereby displacing or flushing pathogens from the GIT [8].…”