The microbiota is intimately related to the health status of the host. Over the last few years, several studies have provided a special emphasis on the essential role of the gut microbiota in central processes, such as nutrition, immunity, and physiology. These studies have also shown that any alteration in this gut microbiota is closely related to human health.

On the other hand, acute infectious diarrhea is one of the leading causes of mortality and morbidity in children worldwide. Understanding the dynamics of recovery from this disease is of clinical interest. As a result, the study published in the journal Frontiers in Microbiology tried to correlate the dynamics of gut microbiota with the evolution of children who were suffering from acute infectious diarrhea caused by rotavirus, and their recovery after the administration of a probiotic, Saccharomyces boulardii CNCM I-745. 

The experiment included 10 children with acute infectious diarrhea caused by rotavirus and 6 healthy children between the age group of 3 and 4 years. In the trial, the children who suffered the rotavirus infection received S. boulardii CNCM I-745 twice daily for the first 5 days of the experiment while the healthy children were given a placebo. On 0, 3, 5, 10, and 30 days after probiotic administration, the fecal samples were collected from each participant in the treatment group. 

Microbial composition was characterized by 16S rRNA gene sequencing. Alpha and beta diversity were calculated, along with a dynamical analysis based on Taylor′s law to assess the temporal stability of the microbiota. 

The findings of the study showed that each ample had an average number of 45,806 sequences with a standard deviation of 12,598 sequences. In particular, the Gamma proteobacteria class was found to be abundant in children with acute diarrhea. The most abundant genus is Bacteroides (13.14%), followed by Faecalibacterium (9.6%) and two unclassified genera from the Ruminococcaceae (9.35%) and Enterobacteriaceae (8.02%) families, respectively. 

Additionally, all children infected with the rotavirus stopped having diarrhea on day 3 after the intervention. The results of the alpha diversity analysis showed a transition from a low-diversity to a high-diversity condition in the first 5 days (p-value < 0.05, Wilcoxon test), larger at 10 and 30 days after probiotic treatment. Most importantly, the microbiota recovered both its diversity and healthy configuration within this period. Canonical correspondence analysis (CCA) showed differences in the gut microbiota of healthy children and of those who suffered from acute diarrhea in the first days, but not in the last days of the experiment. Temporal variability was larger in children infected with the rotavirus than in healthy ones. 

Therefore, it was concluded that gut microbiota seems to play an essential role in diarrhea-related processes. Whether gut microbiota is an active actor or a mere spectator should be addressed in future studies with other experimental designs, and an in-depth study of the functions that carry its different components.

Source: Frontiers in microbiology. 2018 Jun 12;9:1230. DOI: https://doi.org/10.3389/fmicb.2018.01230