Gut microbiota is a group of microorganisms that are deposited throughout the entire gastrointestinal tract. Currently, thanks to genomic tools, studies of gut microbiota have pointed towards the understanding of the metabolism of important bacteria that are not cultivable and their relationship with human homeostasis. Alterations in the composition of gut microbiota could explain, at least in part, some epidemics, such as diabetes and obesity. Likewise, dysbiosis has been associated with gastrointestinal disorders, neurodegenerative diseases, and even cancer. That is why several studies have recently been focused on the direct relationship that these types of conditions have with the specific composition of gut microbiota, as in the case of the microbiota–intestine–brain axis. In the same way, the control of microbiota is related to the diet. Therefore, this review highlights the importance of gut microbiota, from its composition to its relationship with the human health–disease condition, as well as emphasizes the effect of probiotic and prebiotic consumption on the balance of its composition.

Bioactive peptides derived from diverse food proteins have been part of diverse investigations. Whey is a rich source of proteins and components related to biological activity. It is known that proteins have effects that promote health benefits. Peptides derived from whey proteins are currently widely studied. These bioactive peptides are amino acid sequences that are encrypted within the first structure of proteins, which required hydrolysis for their release. The hydrolysis could be through in vitro or in vivo enzymatic digestion and using microorganisms in fermented systems. The biological activities associated with bio-peptides include immunomodulatory properties, antibacterial, antihypertensive, antioxidant and opioid, etc. These functions are related to general conditions of health or reduced risk of certain chronic illnesses. To determine the suitability of these peptides/ingredients for applications in food technology, clinical studies are required to evaluate their bioavailability, health claims, and safety of them. This review aimed to describe the biological importance of whey proteins according to the incidence in human health, their role as bioactive peptides source, describing methods, and obtaining technics. In addition, the paper exposes biochemical mechanisms during the activity exerted by biopeptides of whey, and their application trends.

Many studies have reported the benefits of probiotic microorganisms and the production of angiotensin-converting enzyme (ACE) inhibitors. Determining the proteolytic and ACE inhibition capacities during whey fermentation was the goal of the study. Lacticaseibacillus rhamnosus GG, Streptococcus thermophilus SY-102, and both bacteria together were initially inoculated into whey, reaching an initial concentration of 10⁸ CFU per milliliter in each fermentation system. Through the use of TNBS, SDS-PAGE, and SEC-HPLC methods, the proteolytic profile was examined. An in vitro investigation was performed to test the ACE inhibition capacity. With S. thermophilus, the logarithmic phase of microbial development was shorter than with L. rhamnosus (6 and 12 h, respectively). The logarithmic phase in the co-culture fermentation, however, was extended to 24 h. There were no significant differences in pH between the fermentations. However, the co-culture had a greater concentration of protein hydrolysis (453 ± 0.06 μg/mL), as indicated by the amount of free amino groups. Similarly, this fermentation produced more low molecular weight peptides. The higher inhibition activity, which increased at the conclusion of the fermentation with the co-culture and reached 53.42%, was influenced by the higher peptide synthesis. These findings highlighted the significance of creating useful co-culture products.

This work analyzed the antidiabetic activity of peptides from whey proteins after hydrolysis by Lactobacillus rhamnosus GG and Streptococcus thermophilus SY-102, emphasizing the differences between the proteolytic systems of both bacteria. Peptide fractions from whey proteins may have biological functions, such as antidiabetic functions, which inhibit the DPP-IV enzyme, and lactic acid bacteria could release them. A whey solution of 10% was fermented with selected lactic acid bacteria in monoculture and coculture, analyzing kinetic parameters and the proteolytic profile, using the 2,4,6-trinitrobenzene sulfonic acid technique for free amino groups’ determination and Tris-tricine polyacrylamide gel electrophoresis. An in vitro inhibition assay of the DPP-IV enzyme was used. The kinetic parameters showed a faster duplication rate in the monoculture with L. rhamnosus GG than in the co-culture, which was related to lactic acid production. Co-culture does not have the highest production of free amino groups and peptides. Still, peptide fractions with lower molecular weight (<2 kDa) were found and showed a high DPP-IV inhibitory capacity that was maintained from the middle of the fermentation to the end (55.4%). In comparison, the monoculture of L. rhamnosus GG increased from 0 to 63.3%. This demonstrates that the proteolytic capacity and the proteolytic system of each lactic acid bacteria determine the structure of the released peptides.

Given the rising interest in functional foods for health benefits, this study aims to evaluate the antihypertensive activity of an ice cream base incorporating Lacticaseibacillus rhamnosus GG and aguamiel syrup. We assessed the probiotic viability and ACE inhibitory activity in ice cream enriched with aguamiel syrup compared to inulin. Several reports have highlighted the importance of consuming symbiotic dairy foods to modulate the intestinal microbiota and multiple pathophysiologies. Ice cream has a high worldwide consumption rate, so it is an alternative to incorporating probiotics and prebiotics. The probiotic was inoculated (10⁹ CFU/mL) into an ice cream base enriched with aguamiel syrup and a control base with added inulin. The carbohydrate profiles in the aguamiel (used to produce the syrup) and the aguamiel syrup were obtained through HPLC. TNBS and SDS-PAGE analysis were used to determine the proteolytic action of the probiotic. Sucrose was the carbohydrate with the highest concentration in fresh aguamiel and aguamiel syrup. The probiotic remained viable for 14 days under refrigerated storage conditions, with the aguamiel syrup base showing superior protein hydrolysis (free amino groups 302.67 ± 2.29 µg/mL) and 65% ACE inhibition. Likewise, the pH remained unchanged throughout the refrigerated days. These results underscore the potential of aguamiel syrup as a prebiotic in functional dairy products.