In a recent study published within the journal Nutrients, researchers conducted a scientific review of human clinical trials that examined the administration of oral probiotics to enhance gut microflora and manage type 2 diabetes mellitus.

Study: The Effects of Oral Probiotics on Type 2 Diabetes Mellitus (T2DM): A Clinical Trial Systematic Literature Review. Image Credit: FOTOGRIN / Shutterstock

Background

Type 2 diabetes mellitus is rapidly becoming a serious global health concern. It’s a metabolic disorder where the body either doesn’t reply to insulin or doesn’t produce enough insulin. The insufficient insulin response ends in a rise in blood glucose levels, and the prolonged hyperglycemia eventually affects other organ systems, including the circulatory and nervous systems. The event and progression of type 2 diabetes mellitus is attributed to a mix of metabolic, genetic, and environmental aspects. Nonetheless, despite the genetic predisposition to developing type 2 diabetes mellitus, various modifiable risk aspects comparable to dietary and lifestyle habits can assist within the management of the disease.

Growing evidence indicates that the gut microbiome plays a major role in health and diseases, and dysbiosis within the gut microbiome is linked to the progression of a wide selection of diseases affecting multiple organ systems. Gut microbiome dysbiosis can also be implicated within the etiology of type 2 diabetes mellitus, with the imbalance within the gut microflora abundance and variety having an impact on the glycemic regulation of the host. Using prebiotics and probiotics to modulate the gut microbiome has also been extensively investigated within the context of disease management.

In regards to the study

In the current study, the researchers examined clinical trials which have investigated the effectiveness of oral probiotics within the management of type 2 diabetes mellitus and discussed the species composition of probiotics, in addition to interventions involving combos of probiotics.

The gut microbiome is involved in critical physiological processes comparable to immunity and nutrient absorption. Moreover, studies in non-human mammalian models have clearly shown that metabolic disorders and the gut microbiome are strongly interlinked. Nonetheless, the evidence for this association from human studies stays contentious. Subsequently, only accomplished human clinical trials were included within the review, and people conducted on animal models and reviews and meta-analyses were excluded.

The studies included within the review addressed multiple facets of type 2 diabetes mellitus, comparable to lipid profiles, glycemic metabolism, cardiovascular aspects, fecal evaluation, and inflammation. Only those studies having participants with confirmed type 2 diabetes mellitus were included within the study, and people involving prediabetic patients or conducting comorbidity analyses were excluded. Moreover, studies involving non-oral probiotics or with study participants below the age of 18 were also excluded.

Study characteristics comparable to the form of clinical trial, age of the study population, and variety of participants were collected. Moreover, characteristics of the probiotic intervention, comparable to the common colony forming units administered per day, the duration of the administration, the variety of administrations per day, the probiotic composition, the variety of strains within the probiotics, genus level identification of the microbe species within the probiotic, and the placebos utilized in the study were also obtained from the studies.

The examined outcomes included parameters related to glycemic and lipid levels, kidney and cardiovascular indicators, anthropometric measurements, oxidative stress and other inflammation indicators, and fecal evaluation.

Results

The findings showed that about 64% of the studies included within the review reported an improvement in not less than one in every of the parameters related to the glycemic levels, while 45% of the studies reported improvements in not less than one in every of the parameters related to lipid levels after the administration of oral probiotics. Nonetheless, not one of the studies indicated any uniform improvements in all parameters related to lipid and glycemic levels or blood pressure.

The authors consider that wide-ranging variations within the composition of the probiotics administered, in addition to within the dosage and duration of the probiotic interventions, could explain the inconsistent findings across studies. Nonetheless, the co-administration of oral probiotic interventions together with metformin treatment was found to significantly improve glycemic control in type 2 diabetes patients.

The findings concerning the overall effects of probiotic interventions on inflammation were inconclusive, although just a few studies reported improvements in systolic blood pressure in association with probiotic interventions.

Conclusions

Overall, the findings indicated that administering probiotic interventions for improving gut microbiota in type 2 diabetes patients isn’t related to any antagonistic reactions. In patients undergoing metformin treatment, it significantly improves glycemic control. Additional clinical trials and studies are required to grasp specific aspects, comparable to the impact of various microbial strains and optimal dosage of probiotic interventions to enhance outcomes in type 2 diabetes patients.