Effect of an oral probiotic formula on scalp and facial skin condition, glucose, and lipid metabolism

Objective: We conducted this study to explore the effect of oral probiotic supplementation on hair density as a primary outcome in subjects with hair loss and at high risk of metabolic syndrome. The secondary objectives were to assess probiotic effects on skin barrier function,metabolic health and stress responses.Methods: We supplemented the diets of Chinese adults presenting with hair loss and high risk of metabolic syndrome (n = 26, male gender 38.5%, age = 33.6 ± 4.5 years) with a multi-strain probiotic formula at a dosage of 18.1 billion colony forming units (CFU) twice daily for 12 weeks. We compared the hair density, hair loss, anthropometrics measures, blood biochemistry markers, skin biophysical characteristics and stress-associated responses between baseline and the end of the trial.Results: After 12 weeks of probiotic supplementation, 96.2% of the study participants had improvement in hair density (median density level increased: 1; interquartile range: 1-2). Participants reported reduced hair loss both quantitatively and qualitatively. The majority (73.1%) of the participants reported apparent relief of scalp itching. Stratum corneum hydration and pH increased, while transepidermal water loss and sebum decreased on both scalp and facial skin. Body weight and body mass index decreased following probiotic consumption. Most components of glucose metabolism and the lipid profile were significantly better, with increases in high-density lipoprotein cholesterol and reductions in glucose, homeostasis model assessment-estimated insulin resistance, total cholesterol, non-high-density lipoprotein cholesterol and triglycerides. Inflammation and oxidative stress markers improved with increases in interferon-γ and superoxide dismutase, and reductions in high-sensitivity C-reactive protein, interleukin-6, interleukin-31 and malondialdehyde. No changes were observed in glycated hemoglobin, insulin, immunoglobulin E and interleukin-10 levels. Besides, perceived stress relieved in participants accompanied with improved sleep quality as well as better overall perception of life quality and health.Conclusion: Twice-daily supplementation with the test probiotic formula over a 12-weeks period may exert profound beneficial effects on hair growth, skin condition, glucose and lipid metabolism, and stress-associated psychological and physiological responses in participants presenting with hair loss and high risk of metabolic syndrome. This study has been registered at Chinese Clinical Trial Registry (ChiCTR2100050498).Keywords: hair density, hair loss, metabolic syndrome, oral probiotic supplementation