Evaluation of the antimicrobial attribute of bioactive peptides derived from colostrum whey fermented by Lactobacillus against diarrheagenic E. coli strains.

Colostrum known as "liquid gold" contains approximately 60-80% of whey proteins that can be a great source of bioactive peptide production. Therefore, this study aimed to perform a comparative antimicrobial evaluation of the bioactive peptide generated from L. rhamnosus C25, L. rhamnosus C6, and L. casei NCDC17 fermented colostrum whey. Peptide fractions 10 kDa, 5 kDa, and 3 kDa were isolated using their respective molecular weight cut-off membranes and antimicrobial activity was evaluated against diarrheagenic E. coli strains. The higher inhibition was shown by < 10 kDa peptide fractions from L. rhamnosus C25 fermented colostrum whey and the zone of inhibition was 15 ± 0.06 (E. coli MTCC 723), 17 ± 0.04 (E. coli MTCC 724), 18 ± 0.05 (E. coli MTCC 725), and 17 ± 0.02 (E. coli ATCC 25922). In addition, ST-1 and LT-1 genes of E. coli strains were also confirmed using PCR which is responsible for the diarrheagenic property. Further, the interaction of potent peptides against E. coli strains was also observed by scanning electron microscope. Hence, the significance of the present study emphasized that these bioactive peptides generated from fermented colostrum whey can be used as ingredients in functional food against diarrhoea.

The Functional Interplay between Gut Microbiota, Protein Hydrolysates/Bioactive Peptides, and Obesity: A Critical Review on the Study Advances.

Diet is an essential factor determining the ratio of pathogenic and beneficial gut microbiota. Hydrolysates and bioactive peptides have been described as crucial ingredients from food protein that potentially impact human health beyond their roles as nutrients. These compounds can exert benefits in the body, including modulation of the gut microbiota, and thus, they can reduce metabolic disorders. This review summarized studies on the interaction between hydrolysates/peptides, gut microbes, and obesity, focusing on how hydrolysates/peptides influence gut microbiota composition and function that improve body weight. Findings revealed that gut microbes could exert anti-obesity effects by controlling the host's energy balance and food intake. They also exhibit activity against obesity-induced inflammation by changing the expression of inflammatory-related transcription factors. Protein hydrolysates/peptides can suppress the growth of pro-obesity gut bacteria but facilitate the proliferation of those with anti-obesity effects. The compounds provide growth factors to the beneficial gut bacteria and also improve their resistance against extreme pH. Hydrolysates/peptides are good candidates to target obesity and obesity-related complications. Thus, they can allow the development of novel strategies to fight incidences of obesity. Future studies are needed to understand absorption fate, utilization by gut microbes, and stability of hydrolysates/peptides in the gut under obesity.