Supplementation was found to significantly reduce levels of malondialdehyde; a key end product of polyunsaturated fatty acid peroxidation within the cells.
In addition, total antioxidant capacity (TAC), glutathione (GSH), and nitric oxide (NO) levels were significantly increased following intakes.
The Iranian researchers emphasise: “Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.”
Oxidative stress and health
It is known that oxidative stress occurs following an imbalance of reactive oxygen species (ROS), including superoxide and hydroxy, and the body’s antioxidant defence system. Such stress has been associated with an array of conditions, including cardiovascular disease, diabetes, and Alzheimer's disease.
The consumption of nutritional supplements rich in antioxidants, such as vitamin A, C and E, as well as polyphenols, has been found to enhance the antioxidant defence system. In addition, the efficacies of probiotics for reducing oxidative stress have also been increasingly investigated in recent years, following the identification of gut dysbiosis as a causative factor for oxidative stress.
Studies have identified the successful reversal of dysbiosis and the subsequent increase in beneficial microbial species within the gut following probiotic supplementation. Yet, previous research investigating the reduction of oxidative stress following such interventions has been controversial.
Thus, the present umbrella meta-analysis sought to thoroughly analyse available evidence to conclude on the effect of probiotics on oxidative stress biomarkers in adults.
Review
The researchers searched the databases of Scopus, PubMed, Embase, Web of Science, and Google Scholar to analyse available meta-analyses, resulting in the collation of 15 meta-analyses. Study participants included those aged from 29 to 79, with intervention period ranging over 5 to 14 weeks. Average dosage of probiotics varied from 1 × 1010 to 8 × 1010 CFU.
The probiotic supplements included in the studies contained Lactobacillus, Saccharomyces, and/or Bifidobacterium species.
Following analysis utilising the random-effects model to obtain effect size, it was established that probiotic supplementation significantly reduced serum MDA levels, indicating a reduction in lipid peroxidation levels.
Furthermore, it was reported that TAC, total GSH, and NO levels were significantly increased following supplementation.
The findings highlighted that probiotics delivered in low dosages, for both shorter (<10 -week) and longer (>10-week) durations demonstrated the greatest efficacy in improving antioxidant status.
Explained
“According to our umbrella analysis, probiotics had improving effects on oxidative stress status and antioxidant biomarkers,” the researchers summarise.
Regarding potential mechanisms of action, they hypothesise: “The beneficial effect of probiotics on MDA in the short term may be due to its improving effect on superoxide dismutase (SOD) activity in the early stages of oxidative stress. MDA is a secondary lipid peroxidation product generated by the oxidation of arachidonic acid and larger PUFAs.”
They add that supplementation may benefit those suffering from health conditions such as T2DM, cardiovascular, and autoimmune diseases, yet emphasise that individual studies must further investigate the effects for different conditions.
Source: Frontiers in Nutrition
https://doi.org/10.3389/fnut.2023.1117387
“Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis”
Authors: V. Musazadeh, et al.