1.
Efficacy of diet restriction with or without probiotic for treatment of patients with IBS-D: Phase I-II clinical trial.
Zhao, XS, Shi, LJ, Ning, BL, Zhao, ZM, Li, XX, Zhu, MH, Zhang, YB, Fu, J
Immunity, inflammation and disease. 2023;11(5):e857
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Irritable bowel syndrome (IBS) is a functional intestinal disorder that can significantly affect quality of life. IBS patients suffer from intermittent abdominal pain/ discomfort, altered bowel habits, and abdominal bloating/distension. The aim of this study was to assess the effects of dietary restriction and probiotic use on IBS‐D patients. This study was a 2 × 2 factorial design, single‐centre, randomised trial. Phase 1 was a 12‐week dietary intervention, with 214 participants randomised to an IgG positive restricted diet (IgG res diet) or a control diet (cold/spicy/fried restricted). In Phase 2, 167 participants were randomised into either an IgG res diet + placebo or an IgG res diet + probiotic for 12 weeks. Symptom Severity Scale (IBS‐D‐SSS) and IgG titer were assessed at the beginning and the end of the study. Results showed that both diets reduced IBS‐D symptom severity scores and decreased immunoglobulin (IgG) antibody titer, although the IgG res diet had a greater impact. IBS symptom scores decreased with the addition of a Bifidobacterium probiotic along with dietary exclusion, however, IgG titers did not change with the probiotic compared to placebo. Authors concluded that diet restriction with appropriate and effective probiotics, provides greater symptom reductions for patients with IBS-D.
Expert Review
Conflicts of interest:
None
Take Home Message:
For individuals with IBDS-D:
- Establish IgG intolerances to foods and ensure an elimination diet remains nutritionally balanced
- Consider combining elimination diet with a Bifidobacterium supplement.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
Irritable bowel syndrome (IBS) is a common functional intestinal disorder, affecting 5-20% of the population and diet is likely a major factor in its development as well as in its management. The aim of this study was to compare 3 dietary interventions and the use of a probiotic supplement in patients with IBS-diarrhoea dominant (IBS-D).
Methods
The study was conducted in 2 phases. The first was a 12-week 2 × 2 factorial design, randomised dietary intervention and included 224 patients (214 completed) with IBS-D. The diets were an Eastern/Chinese restriction diet, avoiding cold/raw, spicy and fried foods (CSF), the second avoided common allergens as determined by an IgG test (IgG diet, 14 foods tested), the third a combination of the two, whilst the control group continued their usual (Eastern/Chinese) diet.
The second phase was a 12-week randomised, double-blind, placebo-controlled trial comparing the CSF + IgG diet plus placebo with the CSF + IgG diet plus a 2 billion Bifidobacterium adolescentis supplement; this part included 202 patients of whom 169 completed the study.
The primary outcomes under observation were a reduction in IBS-D symptom severity Score (IBS-D-SSS) and IgG antibody titre (TigG).
Results
Phase 1: The IBS-D-SSS improved in all four groups from baseline (p<0.001), with the intervention groups improving significantly more than the control group (p<0.001). There was no statistically significant difference between the IgG and the IgG + CSF groups, although the authors considered there to be a synergistic effect. Statistically significant (p<0.001) reductions in TIgG were seen in all interventions, but not the control group.
Part 2: Significant (p<0.001) improvements in IBS-D-SSS were seen with both placebo and Bifidobacterium, although this was greater in the probiotic group (p<0.001). Improvements in TIgG were seen in both groups (p<0.001), with no difference between groups.
Conclusion
The authors concluded that the best intervention for patients with IBD-D is an IgG food elimination diet together with a Bifidobacterium probiotic supplement.
Clinical practice applications:
- Consider an elimination diet based on IgG testing for clients with IBS-D
- Consider combining elimination diet with a Bifidobacterium supplement. The dose used in this study was 4x 0.5 billion capsules of Bifidobacterium adolescentis
- Eliminating cold/raw, spicy and fried food could be an alternative to IgG elimination if the latter is not suitable for the client.
Considerations for future research:
- 45% and 35% of screened patients, respectively in the 2 phases of the study, were IgG negative. Screening for more potential food intolerances may extend the suitability of the approach to more patients
- Only a single strain probiotic was tested. Further research could evaluate other or combinations of Bifidobacteria strains in combination with an IgG elimination diet
- The mechanism(s) by which probiotics may affect symptoms of IBS-D are unknown. Adding stool microbiome analyses may shed further light on the effect of the intervention on the composition and function of the microbiome.
Abstract
BACKGROUND AND AIM Diet is a major contributor to irritable bowel syndrome (IBS) and is also a powerful tool for treatment of IBS. This study compared two diets and explored the effectiveness of the diets when combined with a probiotic for treatment of IBS-D patients. METHODS Phase I, patients were randomized into groups; control, cold/spicy/fried restricted diet (CSF res diet), IgG positive restricted diet (IgG res diet), and a combination both diets (CSF + IgG res diet). Phase II, patients were randomized into IgG res diet + placebo and IgG res diet + probiotic. Both interventions were 12 weeks in duration. Symptom Severity Scale (IBS-D-SSS) and IgG titer were assessed at the beginning and the end of the study. RESULTS Totals of 214 and 167 patients completed the two parts of the study, respectively. After intervention, IBS-D-SSS and TIgG grade were significantly improved compared to baseline, with results similar to the control group. In general, there were decreases in IBS-D-SSS and TIgG grade that were significantly different among the groups. There were exceptions; no differences were observed for IBS-D-SSS between the IgG res diet and CSF + IgG res diet, or TIgG grade between the CSF res diet, IgG res diet, and CSF + IgG res diet. However, the CSF res diet and IgG res diet had a synergistic effect that decreased IBS-D-SSS and TIgG titer, with a greater contribution by the IgG res diet. Therefore, we evaluated the IgG res diet with either placebo or probiotic and found that IBS-D-SSS and TIgG grade decreased from baseline. There was a significant decrease in IBS-D-SSS with the probiotic but TIgG grade was not significantly different between the IgG diet + placebo and IgG diet + probiotic diet. CONCLUSIONS Both the CSF res diet and IgG res diet improved IBS symptoms and demonstrated synergy, although the IgG res diet had a greater contribution. Further, when intolerant foods cannot be eliminated from a diet, avoiding uncooked, cold, spicy, fried, and alcoholic foods is a superior choice. The IgG res diet combined with Bifidobacteria was the best dietary choice and may function though a non-IgG pathway.
2.
Comparative analysis of the efficacies of probiotic supplementation and glucose-lowering drugs for the treatment of type 2 diabetes: A systematic review and meta-analysis.
Liang, T, Xie, X, Wu, L, Li, L, Yang, L, Gao, H, Deng, Z, Zhang, X, Chen, X, Zhang, J, et al
Frontiers in nutrition. 2022;9:825897
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Type 2 diabetes (T2D) is a serious medical condition often requiring antidiabetic drug management. Although commonly used antidiabetic drugs effectively control glucose levels, their tolerability profiles differ, causing various side effects. Probiotics can be used as single or multi strains to reduce glycaemic and lipid indicators and avoid the negative effects of antidiabetic medications. The study included twenty-five randomised controlled trials, of which fourteen studies assessed the effectiveness of probiotics (single probiotics, multi-strain probiotics, and probiotics with co-supplements), and eleven studies included different antidiabetic drugs such as Thiazolidinedione (TZD), Glucagon-like peptide-1 receptor agonists (GLP-1 RA), Dipeptidyl peptidase IV inhibitors (DPP-4i), and Sodium-glucose co-transporter 2 inhibitors (SGLT-2i). This systematic review and meta-analysis compared the effectiveness of probiotic and antidiabetic drugs on glycaemia, lipid profile and blood pressure in T2D patients. Probiotics were less effective than specific antidiabetic drugs in reducing fasting blood sugar levels (FBS), HbA1c levels, and triglycerides. Different probiotic formulations were effective in reducing the HOMA-IR index, total cholesterol (TC), triglycerides (TG), and systolic and diastolic pressure (SBP and DBP). A subgroup analysis showed a greater reduction in FBS, HbA1c, TC, TG, and SBP in obese and elderly participants, those who participated for a longer duration, and those from Eastern origins. Considering the high heterogeneity in baseline study characteristics among the studies included in this systematic review and meta-analysis, further studies are required to evaluate the effects of probiotics and antidiabetic drugs. However, healthcare professionals can use the study to understand the effect of probiotics and antidiabetic drugs in reducing glycaemic, lipid and hypertension profiles.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Glucose-lowering drugs, except for DPP-4i, reduced FBS and HbA1c more than probiotics; and SGLT-2i induced the greatest decrease in HbA1c
- A BMI ≥ 30 kg/m2 showed a significant decrease in FBS and the HOMA-IR index compared with those with lower BMI
- Weight loss induced by glucose-lowering drugs and probiotic supplementation plays an important role in glycaemic control in obese patients with type 2 diabetes.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This meta-analysis compared the effects of probiotics and glucose-lowering drugs thiazolidinedione [TZD], glucagon-like pep-tide-1 receptor agonists [GLP-1 RA], dipeptidyl peptidase IV inhibitors, and sodium glucose co-transporter 2 inhibitors [SGLT-2i]) on various outcome measures in patients with type 2 diabetes (T2D).
Methods
A search was performed on PubMed, Web of science, Embase, and Cochrane Library between January 2015 - April 2021.
Results
25 randomised controlled trials (RCT) were included (2843 participants). 14 RCTs (842 participants) involved the administration of single probiotics, multi-strain probiotics, and probiotics with co-supplements, and 11 RCTs (2001 participants) involved TZD, GLP-1 RA, SGLT-2i, and DPP-4i. Participants in 7 of the studies had T2D, aged ≤ 55 years old. 8 RCTs included participants with a mean BMI ≥ 30 kg/m2, and 11 RCTs participants had a mean BMI < 30 kg/m2.
Effects of probiotics:
- Fasting Blood Sugar (FBS): A reduction (−1.42, −0.32 mg/dL, p=0.000)
- Glycated hemaglobin (HbA1c): No reduction (p = 0.000)
- Insulin Resistance (HOMA-IR): A decrease (−0.64, −0.31; p = 0.780), regardless of probiotic strain or with a co-supplement
- Insulin: Not significant (p = 0.000). Subgroup analysis: no reduction
- Total Cholesterol (TC): No difference (p = 0.941). Subgroup analysis: reduction from multi-species probiotics (−0.36, −0.01 mg/dL, p = 0.871)
- Triglycerides: Difference (−0.25 mg/dL, p = 0.958)
- LDL-C: No changes (p = 0.189)
- HDL-C: No increase (p = 0.014)
- Systolic Blood Pressure (SBP): A decrease (−6.44, −0.08 mmHg, p = 0.044)
- Diastolic Blood Pressure (DBP): A reduction (−4.53, −0.80 mmHg, p = 0.206).
Effects of glucose-lowering drugs:
- FBS: A decrease (−4.22 mg/dL, −1.24 mg/dL, p = 0.000)
- HbA1c: A decrease (−2.51%, −0.52%, p = 0.000) with TZD, GLP-1 RA, SGLT-2i, and DPP- 4i; a reduction with SGLT-2i (p = 0.003)
- TC: No difference (p = 0.000). Subgroup: no decrease with single species probiotics and probiotics with co-supplements, TZD, GLP-1 RA, and DPP-4i)
- TG: No difference (p = 0.000)
- . HDL-C: No increase (p = 0.000). Subgroup: a decrease with TZDs (−2.37, −0.72 mg/dL). No difference with probiotic strains, or probiotics with co-supplements, GLP-1 RA, and DPP-4i
- LDL-C: No changes (p = 0.000), Subgroups: no difference with probiotic strains, probiotics with co-supplements, TZD, GLP-1 RA, and DPP-4i).
Limitations
Limited number of studies for TZD and SGLT-2i, making results potentially unreliable.
Conclusions
Multi species probiotics are worth considering as an adjunct to glucose-lowering drugs, and for improving lipid profiles and hypertension.
Clinical practice applications:
- Probiotic supplementation reduced the HOMA-IR index
- Multi-species probiotics were associated with reduction in TC and TG levels
- DPP-4i only decreased TG levels
- TZD was associated with decrease in HDL-C, whereas probiotic supplementation was associated with higher decrease in SBP and DBP and that GLP-1 RA increases the risk of hypoglycaemia.
Considerations for future research:
- Semaglutide was associated with an increased risk for hypoglycaemia compared with a placebo, indicating that the safety of semaglutide needs further study
- Dietary and physical activity should be considered in future studies
- Heterogeneity in some indicators may be due to differences in study baseline characteristics,Larger trials needed to support the results of this meta-analysis.
Abstract
The aim of this systematic review and meta-analysis was to evaluate the effects of probiotics and glucose-lowering drugs (thiazolidinedione [TZD], glucagon-like pep-tide-1 receptor agonists [GLP-1 RA], dipeptidyl peptidase IV inhibitors, and sodium glucose co-transporter 2 inhibitors [SGLT-2i]) in patients with type 2 diabetes from randomized con-trolled trials (RCTs). The PubMed, Web of science, Embase, and Cochrane Library databases were searched on the treatment effects of probiotics and glucose-lowering drugs on glycemia, lipids, and blood pressure metabolism published between Jan 2015 and April 2021. We performed meta-analyses using the random-effects model. We included 25 RCTs (2,843 participants). Overall, GLP-1RA, SGLT-2i, and TZD significantly reduce fasting blood sugar (FBS) and glycated hemoglobin (HbA1c), whereas GLP-1 RA increased the risk of hypoglycaemia. Multispecies probiotics decrease FBS, total cholesterol (TC), and systolic and diastolic blood pressure (SBP, DBP). Moreover, subgroup analyses indicated that participants aged >55 years, BMI ≥30 kg/m2, longer duration of intervention, and subjects from Eastern countries, showed significantly higher reduction in FBS and HbA1c, TC, TG and SBP. This meta-analysis revealed that including multiple probiotic rather than glucose-lowering drugs might be more beneficial regarding T2D prevention who suffering from simultaneously hyperglycemia, hypercholesterolemia, and hypertension.
3.
Effect of a Protein Supplement on the Gut Microbiota of Endurance Athletes: A Randomized, Controlled, Double-Blind Pilot Study.
Moreno-Pérez, D, Bressa, C, Bailén, M, Hamed-Bousdar, S, Naclerio, F, Carmona, M, Pérez, M, González-Soltero, R, Montalvo-Lominchar, MG, Carabaña, C, et al
Nutrients. 2018;10(3)
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Protein supplements are popular among athletes to improve performance and increase muscle mass. However, their effect on other aspects of health is less well known. Dietary changes can affect gut microbiota balance, with beneficial or harmful consequences for the host. This small pilot study was performed on cross-country runners whose diets were complemented with a protein supplement (whey isolate and beef hydrolysate) or maltodextrin (control) for 10 weeks. Microbiota, water content, pH, ammonia, and short-chain fatty acids (SCFAs) were analysed in faecal samples, and oxidative stress markers were measured in blood plasma and urine. Faecal pH, water content, ammonia, and SCFA concentrations did not change, indicating that protein supplementation did not increase the presence of these metabolites of fermentation. Similarly, it had no impact on plasma or urine malondialdehyde levels. Protein supplementation did however increase the abundance of the Bacteroidetes phylum and decrease the presence of health-related taxa including Roseburia, Blautia, and Bifidobacterium longum. The authors concluded that long-term protein supplementation may have a negative impact on gut microbiota. Further research is needed to establish the impact of protein supplements on gut microbiota.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Long-term protein supplementation may have a negative impact on gut microbiota.
- Further research is needed to establish the impact of protein supplements on gut microbiota and whether there is a differential impact between protein from animal and plant sources.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
This is a very interesting study that is relevant to athletic populations.
Clinical practice applications:
Potentially there is a role for probiotics / prebiotics when increasing protein intake (particularly of animal origin) to maintain microbiota diversity and prevent ensuing health complications.
Considerations for future research:
Further, larger scale, research is needed to understand whether the same effect of protein supplementation would be seen with plant-based proteins or whether this is unique to animal based protein supplementation. For example, is the hydrolysation of the proteins to account for the largest effect or could a whole food protein, i.e. not hydrolysed, elicit the same effects?
Also, is this effect seen in other sports, e.g. non-endurance. What about the effect under different conditions e.g. energy deficit vs. energy excess?
Abstract
Nutritional supplements are popular among athletes to improve performance and physical recovery. Protein supplements fulfill this function by improving performance and increasing muscle mass; however, their effect on other organs or systems is less well known. Diet alterations can induce gut microbiota imbalance, with beneficial or deleterious consequences for the host. To test this, we performed a randomized pilot study in cross-country runners whose diets were complemented with a protein supplement (whey isolate and beef hydrolysate) (n = 12) or maltodextrin (control) (n = 12) for 10 weeks. Microbiota, water content, pH, ammonia, and short-chain fatty acids (SCFAs) were analyzed in fecal samples, whereas malondialdehyde levels (oxidative stress marker) were determined in plasma and urine. Fecal pH, water content, ammonia, and SCFA concentrations did not change, indicating that protein supplementation did not increase the presence of these fermentation-derived metabolites. Similarly, it had no impact on plasma or urine malondialdehyde levels; however, it increased the abundance of the Bacteroidetes phylum and decreased the presence of health-related taxa including Roseburia, Blautia, and Bifidobacterium longum. Thus, long-term protein supplementation may have a negative impact on gut microbiota. Further research is needed to establish the impact of protein supplements on gut microbiota.