Comparison of the Effects of Prebiotics and Synbiotics Supplementation on the Immune Function of Male University Football Players

Exercise-induced immunosuppression can increase the risk of respiratory infection and virus-reactivation as the mucosal humoral immunity changes in elite athletes. Meaningful data on the effects of synbiotic and prebiotic supplements in enhancing immune function in football players is lacking. This study compared the effects of long-term prebiotic and synbiotic supplementation on the immunosuppression of male university football players. Thirty male university student-athletes were randomly divided into two groups- the prebiotic group (PG: control group) or the synbiotic group (SG: experimental group). Besides maintaining their normal diet (excluding any fermented foods), participants received 2 g sachets containing either galactooligosaccharides (GOS), fructooligosaccharides (FOS), inulin, polydextrose (PDX), strawberry powder, and maltitol in the PG group or the same formulation with the addition of three probiotic strains in the SG group, once per day for six weeks. The incidence and severity of upper respiratory tract infection (URTI) symptoms, inflammatory markers, and aerobic fitness characteristics after daily high-intensity training and a one-time strenuous exercise were studied. A significant decrease was observed in URTI incidence and duration in the SG group compared to the PG group, as well as a significant decrease in interleukin-4 (IL-4), IL-10, and transforming growth factor-β1 (TGF-β1) levels in both groups following the constant load exercise. A significant decrease was also observed for maximal heart rate (HRmax) and lactic acid elimination rate (ER) in the SG group, but not in the PG group during the constant load experiment and recovery period, respectively. These results give an indication of the positive effects of 6-week synbiotic supplementation on the immune function and athletic performance of male university football players. 

Key takeaways:

• Elite athletes are at an increased risk of opportunistic infection and virus reactivation due to exercise-induced immunosuppression.
• Synbiotics may be more effective than prebiotics in improving immune function in male university football players.
• The synbiotic effect may be manifested through a reduction in the incidence and duration of URTI and improving lactate metabolism and exercise performance.

Access to the study: https://pubmed.ncbi.nlm.nih.gov/36904156/ 

Reference: Zhang, L., Xiao, H., Zhao, L., Liu, Z., Chen, L., & Liu, C. (2023). Comparison of the Effects of Prebiotics and Synbiotics Supplementation on the Immune Function of Male University Football Players. Nutrients, 15(5), 1158. https://doi.org/10.3390/nu15051158

Probiotics and Prebiotics in Subclinical Hypothyroidism of Pregnancy with Small Intestinal Bacterial Overgrowth 

Subclinical hypothyroidism (SCH) refers to elevated thyroid-stimulating hormone (TSH) levels and normal serum tetraiodothyronine (T4) levels and affects 2.0-2.5% of pregnancies in the United States (US). Studies have shown an elevated incidence of spontaneous abortions, placental abruption, and premature rupture of membranes in pregnant women with SCH. This study explored the effects of combining probiotics and prebiotics on thyroid function and small intestinal bacterial overgrowth in SCH pregnant women complicated with small intestinal bacterial overgrowth (SIBO). Seventy-eight pregnant women with SCH (SCH group) and 74 healthy pregnant women (control group) were recruited, with all participants in their second trimester. Differences in high sensitivity C-reactive protein (hs-CRP), the result of lactulose methane-hydrogen breath test, and gastrointestinal symptoms assessed by GSRS scale were analyzed. In the SCH group, forty-seven women had SIBO, and 32 of the 47 received the intervention (1.5 g of a probiotic containing Bifidobacterium infantis, Lactobacillus acidophilus, Enterococcus faecalis, and Bacillus cereus and 5 g of a prebiotic composed of inulin, ice sugar, microcrystalline cellulose, and oat fiber) three times/day for 21 days. The study reported a strong association between SIBO and SCH in pregnancy and an improved SIBO in pregnant women with SCH taking the combination of probiotics and prebiotics. As such, the study gives insight into the potential use of probiotics with prebiotics for SIBO treatment in SCH pregnant women. 

Key takeaways:

• SCH is prevalent in pregnancy, affecting 2.0-2.5% of those in the US, and refers to increased TSH and normal T4 levels.
• Consumption of probiotics with prebiotics may improve small intestinal bacterial overgrowth and thyroid function in SCH pregnant women.
• Probiotics combined with prebiotics may be effective as a potential treatment for SIBO in pregnant women with SCH.

Access to the study: https://pubmed.ncbi.nlm.nih.gov/37032411/ 

Reference: Ouyang, Q., Xu, Y., Ban, Y., Li, J., Cai, Y., Wu, B., Hao, Y., Sun, Z., Zhang, M., Wang, M., Wang, W., & Zhao, Y. (2023). Probiotics and Prebiotics in Subclinical Hypothyroidism of Pregnancy with Small Intestinal Bacterial Overgrowth. Probiotics and antimicrobial proteins, 10.1007/s12602-023-10068-4. Advance online publication. https://doi.org/10.1007/s12602-023-10068-4 

Role of human milk oligosaccharide metabolizing bacteria in the development of atopic dermatitis/eczema

Atopic dermatitis (AD), also known as eczema, is an inflammatory skin condition that affects up to 20% of infants in the US. Despite an increase in cases in recent years, a cure remains unavailable for AD. Atopy usually manifests during the first six months of an infant’s life, including itchy and painful skin and sleep disruptions. This condition is one of the predictors of later allergic or other hyperinflammatory health issues (i.e., asthma, rhinitis, or food allergies). Previous data has suggested that a diet of human milk may offer protection against AD, specifically with the prebiotic and immunomodulatory effects of human milk oligosaccharides (HMOs) on the infant immune system. This review employed a narrative review methodology to locate literature published in three databases, focusing on publications within the last five years. It reported on the protective role of specific HMO metabolism gene sets and HMO metabolites against the development of atopy through interactions with the immune system. It presented evidence of the diversity of HMOs, microbes, and metabolites among exclusively breastfed infants, suggesting that specific repertoires of microbial genes and gene products may be necessary for human milk to protect against AD in infancy. Detailed metagenomic studies of the infant gut microbiota and its associated metabolomes are needed to elucidate the relationship between human milk feeding during infancy on the development of AD/eczema.

Key takeaways:

• AD is a common condition that manifests during the first six months of life and predisposes individuals to allergic and hyperinflammatory health problems later in life. 
• HMOs, an essential component of human milk, possess prebiotic and anti-inflammatory properties and may play a role in protecting against developing AD.
• The protective role of human milk is most likely determined through the specific genes and metabolites produced by HMO-metabolizing bacteria in the intestinal microbiota. 

Access the study: https://pubmed.ncbi.nlm.nih.gov/37020647/ 

Reference: Rahman, T., Sarwar, P. F., Potter, C., Comstock, S. S., & Klepac-Ceraj, V. (2023). Role of human milk oligosaccharide metabolizing bacteria in the development of atopic dermatitis/eczema. Frontiers in pediatrics, 11, 1090048. https://doi.org/10.3389/fped.2023.1090048 

A comparison of the effects of resistant starch types on glycemic response in individuals with type 2 diabetes or prediabetes: A systematic review and meta-analysis 

Type 2 diabetes (T2D) is a chronic elevation in blood glucose concentrations caused by insulin resistance or defected insulin secretion. Dietary interventions such as resistant starch (RS) can potentially alleviate T2D symptoms, including lowering the glycemic load and attenuating postprandial glucose and insulin responses. This systemic review and meta-analysis compared the effects of different RS types – type 1 in intact plant cell structures and type 2-5 in modified starch molecules – on fasting and postprandial glycemia in subjects with T2D and prediabetes. Five databases were searched for relevant randomized controlled trials (RCTs), retrieving 36 RCTs with 982 participants, of which 31 were used in the meta-analysis. Subgroup analyses between subjects with T2D versus prediabetes and RS types were conducted. Changed glucose homeostasis was reported with RS types 1 and 2 via discrete mechanisms with different influences on glycemia. RS use as a dietary intervention in T2D or prediabetic patients may prevent further deterioration of glycemic control. Further research is required to elucidate the effect of RS types 3, 4, and 5 on glucose metabolism. 

Key takeaways:

• T2D is a global concern being the ninth leading cause of death worldwide. 
• Dietary interventions, including RS, may alleviate T2D symptoms and complications by lowering the glycemic load and attenuating postprandial glucose and insulin responses.
• The influence of types 1 and 2 RS on lowering postprandial glucose is comparable, with type 2 also affecting fasting glucose and insulin.
• Different RS types exert their effects on glucose homeostasis via various mechanisms.

Access the study: https://pubmed.ncbi.nlm.nih.gov/37051127/ 

Reference: Pugh, J. E., Cai, M., Altieri, N., & Frost, G. (2023). A comparison of the effects of resistant starch types on glycemic response in individuals with type 2 diabetes or prediabetes: A systematic review and meta-analysis. Frontiers in nutrition, 10, 1118229. https://doi.org/10.3389/fnut.2023.1118229