Gut microbiota is a pivotal factor in delineating human health and well-being. Thus, there is a tremendous interest in food processing effect on composition and function of the endogenous microbiota. Studies have demonstrated thermal processing, including the Maillard reaction that may occur even unintentionally during heating of protein-carbohydrate mixtures, alters protein digestibility. However, gaps exist in understanding how processing can be harnessed to impact protein digestive fate, particularly the gut microbiome.
This work focused on prebiotic FOS and bovine lactoferrin, a whey protein encrypting for bioactive peptides, e.g. antimicrobial and bifidogenic. Lactoferrin was processed via controlled dry-heating (60oC, 79%RH), with and without FOS to isolate the Maillard reaction effect. Samples were predigested in an in vitro gastro-duodenal model. Resulting digesta was fed to an in vitro batch colon model inoculated with adult human feces to study fermentability. Samples were collected at different time points and analyzed for microbial composition by DNA sequencing of 16s rRNA amplicons using Illumina MiSeq. Lactoferrin digesta, either of native form, heated or conjugated with FOS (MLf) resulted in alterations to the gut microbiota, but produced a generally similar bacterial profile. This included enrichment in Enterobacteriaceae and a notable decrease in Bacteroides compared to FOS. In addition, an increase in Acidominococcus was detected at fementation end point which was not detected in the FOS control. Moreover, Bifidobacteriaceae/Bifidobacterium relative abundance was lower in the MLf vessel compared to FOS. Overall, this study offers a holistic approach to facilitate rational development of products designed to benefit the consumer.
