Parasitic diseases remain an important problem today. Recently, many cases of combined invasion have been registered. Mixed invasion by Giardia and roundworms is the most common in Ukraine. The clinical picture of the disease is characterized by damage to various organs and systems, but most often in patients the manifestations relate to the primary site of parasitism of pathogens - the gastrointestinal tract, which is often accompanied by disruption of the intestinal microflora. The aim was to study the effect of probiotics containing bicarbonate saccharomycetes in the complex therapy of patients with giardiasis, ascariasis, and combined invasion. We examined 90 patients with giardiasis, ascariasis, and combined invasion, divided into 3 groups, depending on the type of invasion, each of which is divided into two subgroups, depending on the treatment (basic treatment and with the addition of probiotics). It was administered orally 1 capsule 2 times a day for 14 days. 1 capsule contains 250 mg of saccharomycetes and excipients. The control group consisted of 20 healthy individuals. The state of the intestinal microflora was determined using a classical microbiological study of feces to determine the population level of the microflora according to VA Znamensky. The research was performed twice: before treatment and 14 days after treatment. The diagnosis of giardiasis and ascariasis was confirmed by detection of the pathogen in the feces by parasitoscopy of feces. When studying the state of the intestinal microflora, it was found that all patients had the following changes before treatment. The content of bifidobacteria, lactobacilli, enterococci and the total content of E. coli was reduced. At the same time, there was an increase in the content of peptococci, bacteroids, Escherichia coli with weakly enzymatic properties, haemolytic Escherichia coli, fungi of the genus Candida and staphylococci. After the basic treatment, some positive changes were observed in all groups of patients, but the content of autochthonous flora still decreased, the presence of pathogenic bacteria (staphylococci) and fungal flora was noted. The content of bifidobacteria was slightly reduced. The quantitative composition of lactobacilli was higher than before treatment. Patients had a reduced amount of bacteroids, total Escherichia coli, although its content was higher than before treatment. An elevated level of Escherichia coli with weak enzymatic properties was noted. Hemolytic Escherichia coli was present, as well as the number of enterococci. Fungi of the genus Candida were available also. In the 3b group of patients there were more significant signs of improvement in the microflora.
 After the inclusion in the treatment complex of probiotics containing saccharomycetes of billard, according to the results of bacteriological research, there was a significant positive dynamic of the intestinal microflora. The content of bifidobacteria was significantly higher compared to the other two groups. The quantitative composition of lactobacilli was slightly reduced. The amount of bacteroids was normalized. The total content of Escherichia coli increased, there was a decrease in the content of Escherichia coli with weak enzymatic properties. In addition, the presence of haemolytic Escherichia coli was detected in only one patient. Almost complete normalization of the level of enterococci was observed. From the fungal flora, the level of fungi of the genus Candida was minimal, comparing similar results of other groups.