Impact of Three Bovine Plasma Protein Fractions on the Human Gut Microbiota

Abstract

The gut microbiome plays a crucial role in the health of its host by regulating metabolism and protecting against pathogens. One of the key functions of the gut microbiome is to produce short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate. Though each SCFA has distinct health benefits, all SCFAs have anti-inflammatory effects and decrease the pH of the colonic lumen which increases mineral absorption and inhibits the growth of pathogens. Previous studies show that various fractions of bovine plasma positively impact the gut health, though their effect on the microbiome and SCFA levels is unknown. The objective of our study is to examine the effect of different bovine plasma fractions (whole plasma, crude bovine serum albumin [BSA], and immunoglobulins [SBI]) on the SCFA composition of the gut microbiome. We hypothesize that the bovine plasma fractions will alter the microbiome with an increase of SCFA abundance, with each of the three fractions performing uniquely.SIFR technology (Cryptobiotix) was used to investigate the effects of the three plasma products on the fermentation of fecal microbiota samples provided by six donors. Each protein fraction was subjected to oral, gastric, and small intestinal digestion, simulated small intestinal absorption, and colonic fermentation. Samples were analyzed by examining metabolic activity metrics, including the pH, gas levels, abundance of various SCFAs and branched-chain fatty acids (BCFAs), and microbial composition by quantitative 16S rRNA gene profiling. The addition of any of the three bovine plasma fractions (5 g) showed significant changes in microbial activity, including the increase in acetate, propionate, and butyrate (p < 0.001), with the addition of SBI having the largest effect, followed by whole plasma then BSA. The increase in the SCFAs was accompanied by an increase of bacteria known to produce SCFAs for all dosed protein fractions, with the SBI fraction giving significant increases in Firmicutes (p < 0.05) and Bacteroides (p < 0.01) compared to the blank. Overall, the addition of bovine plasma fractions into an in vitro gut model increases SCFAs, including acetate, propionate, and butyrate, with SBI showing the largest impact. Though SBI is known to bind and neutralize opportunistic pathogens by immune and steric exclusion mechanisms in the gut, this work suggests that SBI further promotes gut health by increasing SCFAs and the bacteria that produce them. Commercial - Proliant Health and Biologicals funded the research. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.