1 Active Nutrition, DuPont Nutrition & Health, Sokeritehtaantie 20, 02460 Kantvik, Finland.
Benef Microbes. 2017 Apr 26;8(2):143-151. doi: 10.3920/BM2016.0140. Epub 2016 Dec 23.
The probiotic definition requires the administration of an 'adequate amount' in order to obtain a health benefit. What that amount should be is not indicated. Here, an overview is given of studies that investigated the dose-response relation of probiotics in human interventions. Studies were divided in; meta-analyses, meta-analyses on specific probiotic strains, and studies testing two or more doses of a probiotic (combination) in the same study. Meta-analyses on the effect of probiotics on antibiotic associated diarrhoea (AAD) suggest a dose-response effect; for Clostridium difficile-associated diarrhoea on the other hand no dose-response was observed. For other end-points; such as necrotising enterocolitis, prevention of atopic dermatitis and slow intestinal transit, no dose-response relation was identified in meta-analyses. For prophylaxis in colorectal cancer and relief of irritable bowel syndrome, no dose-response relation was determined. However, for blood pressure, a meta-analysis observed that higher doses (greater than 10 cfu) were more effective than lower doses. Meta-analyses of specific strains suggest a break-point for effectiveness of Lactobacillus rhamnosus GG in the treatment of acute gastroenteritis in children; no dose-response was observed for two other probiotics assessed. Studies comparing two or more doses indicate that faecal recovery and risk reduction of AAD follow a positive dose-response relationship. Other end-points such as immune markers, general health, and bowel function did not exhibit clear dose-response relations. For AAD, the findings are very compelling; both meta-analyses and dedicated dose-response studies observe a positive correlation between dose and AAD risk. These findings do not allow for extrapolation, but suggest that studying higher doses for this end-point would be worthwhile. The lack of a clear dose-response for other end-points, does not mean it does not exist; present data does just not allow drawing any conclusions.
益生菌的定义需要摄入“足够量”才能获得健康益处。但具体应该摄入多少量并没有说明。本文综述了研究益生菌对人类干预的剂量反应关系的研究。研究分为：荟萃分析、特定益生菌菌株的荟萃分析以及在同一研究中测试两种或多种益生菌剂量（组合）的研究。荟萃分析表明益生菌对抗生素相关性腹泻（AAD）的影响存在剂量反应关系；然而，对于艰难梭菌相关性腹泻，没有观察到剂量反应关系。对于其他终点，如坏死性小肠结肠炎、预防特应性皮炎和减缓肠道转运，荟萃分析未确定剂量反应关系。对于结直肠癌的预防和肠易激综合征的缓解，也没有确定剂量反应关系。然而，对于血压，一项荟萃分析观察到高剂量（大于 10 cfu）比低剂量更有效。对特定菌株的荟萃分析表明，在治疗儿童急性胃肠炎方面，鼠李糖乳杆菌 GG 的有效性存在一个临界点；对于另外两种评估的益生菌，没有观察到剂量反应关系。比较两种或更多剂量的研究表明，粪便恢复和 AAD 风险降低呈正剂量反应关系。其他终点，如免疫标志物、一般健康和肠道功能，没有表现出明显的剂量反应关系。对于 AAD，研究结果非常有说服力；荟萃分析和专门的剂量反应研究都观察到剂量与 AAD 风险之间存在正相关。这些发现不允许推断，但表明研究该终点的更高剂量是值得的。对于其他终点，没有明确的剂量反应关系并不意味着不存在；目前的数据只是不允许得出任何结论。
