In this work, we compared composition of the intestinal microbiota of healthy volunteers and patients with irritable bowel syndrome (IBS) in Hanoi residents before and after therapy with a probiotic starter culture based on the bacteriocinogenic strain Enterococcus faecium L3 (L3), which is successfully used to correct dysbiosis and treat IBS in Russia. In IBS patients (IBS group) α-diversity was higher than in the control group (Healthy) and in IBS patients after probiotic therapy (IBS + L3 group). Phylogenetic analysis of the studied samples reflected the division of the studied communities into 2 clusters, one of which grouped samples, mainly taken for IBS before therapy. Principal component analysis (PCoA) showed that most of the samples from the IBS group are located on the graph in a separate sector, far from the adjacent IBS + L3 and Нealthy samples. A study of the microbiome of Vietnamese patients with IBS after taking probiotic at the level of types (phyls) revealed a tendency towards an increase in the representation of Firmicutes. The introduction of L3 led to an increase in the population of members of the family Lachnospiraceae, such as butyrate-producing Roseburia and acetate-producing Blautia. At the same time, the percentage of staphylococci and bacteria belonging to the Enterobacteriaceae family was decreased. In addition to positive changes in the functioning of the gastrointestinal tract, revealed on the basis of clinical data, the features of the intestinal microbiota of IBS residents of Hanoi compared with healthy volunteers and in the same patients after probiotic therapy were revealed by metagenomic analysis of 16S rRNA genes. Positive shifts in the intestinal microbiome of IBS patients in Vietnam after therapy with a probiotic starter culture based on L3 do not fundamentally differ from the previously described effects noted by the authors when using this probiotic in Russia, which creates the preconditions for expanding the possibility of its use in the Asian region.