Effects of Probiotics, Prebiotics, and Synbiotics on Calcium Homeostasis and Bone Health With Aging: A Systematic Review.

BACKGROUND: Calcium homeostasis and bone health are an increasing concern for middle-aged and older adults. Many studies have explored the positive effects of probiotics, prebiotics, or synbiotics on serum calcium and bone mineral density (BMD) or other parameters related to bone health. However, the participants, the species, doses and duration of interventions, outcomes, and measurements varied among these studies. AIMS: To systematically evaluate the effect of probiotics, prebiotics, or synbiotics on maintaining calcium homeostasis and improving bone health in middle-aged and older adults. METHODS: We identified studies in Cochrane Library, Embase, PubMed, Web of Science, CINAHL, China National Knowledge Infrastructure, and Wanfang and articles in English and Chinese published from inception up to January 10, 2019. Randomized controlled trials (RCTs) involving probiotics, prebiotics, or synbiotics for middle-aged or older adults were employed for meta-analysis by using RevMan 5.3, and heterogeneity and risk of bias assessment were performed. RESULTS: A total of eight studies, involving 564 participants, were included. Probiotics, prebiotics, or synbiotics supplementation was able to significantly elevate serum calcium levels (0.52 mg/dl, 95% CI [0.38, 0.66]), heterogeneity: p = .13, I2  = 44%), while the results of meta-analysis failed to support the effects of this supplementation on the parameters related to bone health in middle-aged and older adults, including BMD, parathyroid hormone, osteocalcin, and alkaline phosphatase. LINKING EVIDENCE TO ACTION: Probiotics, prebiotics, or synbiotics supplementation exerts a facilitating influence on the level of serum calcium, while the present study has not yet supported the beneficial effects of such interventions on bone health. Therefore, further studies with high-quality RCTs are required to determine the effects of probiotics, prebiotics, or synbiotics supplementation on middle-aged and older adults.

Application of evidence on probiotics, prebiotics and synbiotics by food industry: a descriptive study.

BACKGROUND: This study assessed how the food industry applies the knowledge and evidence gained from synbiotics, probiotics or prebiotics research in infants, on the general paediatric population. This study also explored: what happens after the clinical trials using infant formula are completed, data is published or remains unpublished; the effectiveness and type of medium the formula manufacturers use to educate consumers on probiotic, prebiotic or synbiotic infant formula. FINDINGS: This was a descriptive study (a survey) that used a structured questionnaire. All listed companies that manufacture and / or market food products with added probiotics, prebiotics or synbiotics for infants were identified and invited to participate. People responsible for research and development were invited to participate in the survey. A letter of invitation was sent to selected participants and if they expressed willingness to take part in the study, a questionnaire with a written consent form was sent. Descriptive statistics and associations between categorical variables were to be tested using a Chi-square test, a p < 0.05 was statistically significant.A total of 25 major infant formulas, baby food manufacturers were identified, invited to participate in the survey. No company was willing to participate in the survey for different reasons: failure to take any action 5 (20%), decision to participate indefinitely delayed 2 (8%), sensitivity of requested information 3 (12%), company does not conduct clinical trials 1 (4%), company declined without further information 4 (16%), erroneous contact information 6 (24%), refusal by receptionists to forward telephone calls to appropriate staff 3 (12%), language barrier 3 (12%), company no longer agrees to market research 1 (4%). CONCLUSION: Due to a poor response rate in this study, no conclusion could be drawn on how the food industry applies evidence gained through probiotics, prebiotics or synbiotics research on infants for the benefit of the general paediatric population. More information and greater transparency is needed from the infant formula manufacturers on how they apply the evidence gained from the research on probiotics, prebiotics and synbiotics on infants.