Introduction: There is growing evidence from animal and clinical studies suggesting probiotics can positively affect type 2 diabetes (T2D). In a previous randomized clinical study, we found that administering a live multistrain probiotic and absorbent smectite once a day for eight weeks to patients with T2D could reduce chronic systemic inflammatory state, insulin resistance, waist circumference and improve the glycemic profile. However, there is a lack of evidence supporting the efficacy of probiotic co-supplementation with absorbent smectite on pancreatic b-cell function in T2D.

Aim: This secondary analysis aimed to assess the effectiveness of an alive multistrain probiotic co-supplementation with absorbent smectite vs placebo on b-cell function in T2D patients.

Material and methods: We performed a secondary analysis on a previously published randomized controlled trial (NCT04293731, NCT03614039) involving 46 patients with T2D. The main inclusion criteria were the presence of b-cell dysfunction (%B<60%) and insulin therapy alone or combined with oral anti- diabetic drugs. The primary outcome was assessing b-cell function as change C- peptide and %B.

Results: We observed only a tendency for improving b-cell function (44.22 ± 12.80 vs 55.69 ± 25.75; р=0.094). The effectiveness of the therapy probiotic- smectite group was confirmed by fasting glycemia decreased by 14% (p=0.019), HbA1c – 5% (p=0.007), HOMA-2 – 17% (p=0.003) and increase of insulin sensitivity by 23% (p=0.005). Analysis of the cytokine profile showed that statistical differences after treatment were in the concentration of both pro- inflammatory cytokines: IL-1b (22.83 ± 9.04 vs 19.03 ± 5.57; p=0.045) and TNF-a (31.25 ± 11.32 vs 26.23 ± 10.13; p=0.041).