State of intestinal microbiome in patients with osteoarthritis

Objective — to study the composition of intestinal microflora (CM) in patients with osteoarthritis (OA) against the background of administration of non-steroidal anti-inflammatory drugs (NSAIDs) and without them, as well as define difference in the CM of patients and healthy subjects.Materials and methods. The study involved 26 OA patients, who were divided into two groups: 16 subjects on NSAIDs (NSAID group) and 10 patients who did not take NSAIDs (non-NSAID group). Control group consisted of 23 healthy individuals. The state of intestinal microbiome was studied by real-time PCR, with the determination of the content of Bacteroides, Firmicutes, Actinobacteria, «other» types (total bacterial RNA with the exception of the above types) and the ratio of Firmicutes/Bacteroides.Results. It following significant differences have been established in QA patients in comparison with the healthy controls: Bacteroides levels was significantly higher, the median 19 % (interquartile range 8.05 — 27.39) % versus 7.36 (3.69 — 9.22) %, p < 0.001; the Firmicutes and Actinobacteria levels were lower (51.47 (45.05 — 56.13) % versus 71.53 (58.57 — 74.098) %, p < 0.01) and (6.95 (4.71 — 9.25) % versus 10.56 (7.07 — 14.64) %, p < 0.05), respectively. The Firmicutes/Bacteroides ratio was almost five times lower in the OA group than in healthy control (2.81 (1.73 — 6.48) versus 9.898 (6.37 — 18.81), p < 0.001), which makes it a very important diagnostic criterion. No significant difference was reveled in the CM compositions between the patients of NSAID group and non-NSAID group, as well as in the Firmicutes/Bacteroides ratio. However, Bacteroides levels differed form healthy controls in a higher extent in the group of OA patients from non-NSAID group, and they demonstrated more low Actinobacteria levels than healthy controls. Moreover, a middle-strength correlation has been established between the age and fecal Bacteroides content (positive, ρ = 0.595, p < 0.001) and between age and fecal Firmicutes content (negative, ρ = –0.523, p < 0.001). A positive correlation of the average strength was established between the «other» types of flora and age (ρ = 0.325, p < 0.05)and body mass index (ρ = 0.464, p < 0.05), which is consistent with the previous literature data.Conclusions. The significant difference has been established in the intestinal microflora composition between the group of OA patients and healthy subjects, and absence of such difference in case of subgroups comparison. The most significant difference was reveled in the levels of Bacteroides and Firmicutes: an increase of Bacteroides level and decrease in Firmicutes and Actinobacteria levels. The Firmicutes/Bacteroides ratio was the most sensitive indicator. In terms of Bacteroides levels, the non-NSAID group differed from the control group in more extension than the NSAID group, and they had the low Actinobacteria level.