Human Microbiome and Probiotics: Nestle

Speaker: Dr. R Ajanthan, Senior Consultant Paediatrician, Colombo. Presented at: Nestlé Nutrition Institute Workshop, Negomb, Sri Lanka

Summary

The topic focuses on the changes in the human microbiome and its definition with differing situations – Mode of Delivery, Mode of Feeding, Recurrent Illness & Treatment and the changes in composition and function with age. Human Microbiome is the collective of genomes and gene products of the resident microbes living within and on humans. In the second part of the talk, Dr. Ajanthan focuses on the thousand day’s concept, which is increasingly being recognized as an important window of opportunity i.e. beginning from the first day of pregnancy, till completion two years of the child’s life.

Human body is home to more than 1 trillion microbes. Gastrointestinal tract alone harbours a diverse array of commensal microbes that contribute to host nutrition developmental regulation of intestinal angiogenesis, protection from pathogens and development of the immune response. Start of a woman’s pregnancy until her child’s 2nd birthday is a 1000 day period. It offers a unique window of opportunity to shape healthier and more prosperous futures. The right nutrition during this 1,000 day window can have an enormous impact on a child’s ability to grow, learn, and rise out of poverty. It can also have a profound effect on the long-term health, stability, and development tire communities and nations.

Human Microbiome is the collective genomes and gene products of the resident microbes living within and on humans. The advent of new molecular technologies has been useful in the detection of uncultured microbes and may enable more microbes to be cultured in the future. Fluorescence in situ hybridization (FISH), DNA pyrosequencing, Microarrays (PhyloChip), Quantitative polymerase chain reaction assays are some of these technologies. Microbiome in general is predominant bacterial phyla (composed of hundreds of bacterial genera and species) in the human body, regardless of body site; include Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria. Recent metagenomic studies suggest that the gut microbiota of school—age and adolescent children differ significantly from that of adults. This indicates that the human microbiome may be evolving during childhood and adolescence.

Recent studies of infants with NEC found increased abundances of Proteobacteria including Citrobacter sp in faecal microbiota. Furthermore, Neu et al recently described a greater proportion of Gammaproteobacteria in faecal microbiota prior to the diagnosis of NEC in infants. Treatment and Manipulation of the Human Microbiome can be done by Microbial supplements (probiotics or synbiotics), Foods or substrates (diet or prebiotics), Microbial suppression or elimination (antibiotics).

Probiotics’ inherent biological features enable them to predominate and prevail over potential pathogenic microorganisms in the human digestive tract. It is currently hypothesized that these microbes generate small molecular metabolic by-products that exert beneficial regulatory influence on host biological functions, including short—chain fatty acids such as butyrate. Addition of probiotics to powdered infant formulas has not been demonstrated to be harmful to healthy term infants. On the other hand, evidence of clinical efficacy for their addition is insufficient to recommend the routine use of these formulas. No RCTs have directly compared the health benefits of feeding human milk versus infant formula supplemented with probiotics.