Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Department of Pediatrics, Slagelse Hospital, Slagelse, Denmark.
Pediatr Res. 2021 Feb;89(3):563-568. doi: 10.1038/s41390-020-0895-5. Epub 2020 Apr 19.
Probiotics are known to stimulate the immune system but the effect on thymus size in late infancy is unknown. We examined the effect of probiotics on thymus size and C-reactive protein (CRP) in healthy Danish infants starting daycare. We further examined associations between thymus size, CRP and recent infections.
The study included 186 children randomized to a combination of Lactobacillus rhamnosus, LGG® and Bifidobacterium animalis spp. lactis, BB-12® or placebo for 6 months. Thymus size, assessed as thymus index (TI) and thymus weight index (TWI), was measured by ultrasound at baseline and at endpoint. Blood samples were drawn to measure CRP. Infections were parent-reported.
There was no significant difference in thymus size between the probiotic group and placebo (p ≥ 0.248) but TWI tended to be higher in the probiotic group corresponding to 5% higher than placebo (p = 0.068) in an adjusted model. There was no effect of probiotics on CRP (p = 0.331). At the endpoint, thymus size was inversely associated with CRP (p ≤ 0.040), diarrhea (p ≤ 0.050), and TI was also associated with the absence from daycare due to respiratory or gastrointestinal infections (p = 0.010).
The probiotic intervention had no effect on thymus size or CRP in Danish children at the age of starting daycare.
Overall there was no effect on thymus size of a combination of Lactobacillus rhamnosus, LGG® and Bifidobacterium animalis spp. lactis, BB-12® administered to Danish children starting daycare. This study examines the effect of probiotics on thymus size in healthy children when they start daycare thus exposed for infections while their immune system is still developing. This has to our knowledge not been described before. We found no significant difference in thymus size between the probiotic and placebo groups, but for thymus weight index, there was a trend. This should be investigated further in studies designed for this as primary outcome.
益生菌已知可刺激免疫系统，但对婴儿后期胸腺大小的影响尚不清楚。我们研究了益生菌对开始日托的健康丹麦婴儿的胸腺大小和 C 反应蛋白（CRP）的影响。我们进一步研究了胸腺大小、CRP 与近期感染之间的关联。
该研究纳入了 186 名儿童，他们被随机分为以下两组：服用含有鼠李糖乳杆菌、LGG®和动物双歧杆菌乳亚种、BB-12®的组合 6 个月或安慰剂。在基线和终点时，通过超声测量胸腺大小，评估为胸腺指数（TI）和胸腺重量指数（TWI）。采集血样测量 CRP。感染情况由家长报告。
益生菌组与安慰剂组的胸腺大小无显著差异（p≥0.248），但在调整后的模型中，益生菌组的 TWI 倾向于比安慰剂组高 5%（p=0.068）。益生菌对 CRP 无影响（p=0.331）。在终点时，胸腺大小与 CRP 呈负相关（p≤0.040），与腹泻呈负相关（p≤0.050），TI 还与因呼吸道或胃肠道感染而缺勤有关（p=0.010）。
在开始日托的丹麦儿童中，益生菌干预对胸腺大小或 CRP 没有影响。
总的来说，在开始日托的丹麦儿童中，服用含有鼠李糖乳杆菌、LGG®和动物双歧杆菌乳亚种、BB-12®的组合对胸腺大小没有影响。本研究检测了益生菌对健康儿童开始日托时胸腺大小的影响，因为此时他们的免疫系统仍在发育，易受感染。据我们所知，这在以前的研究中尚未描述过。我们没有发现益生菌组和安慰剂组的胸腺大小有显著差异，但对于胸腺重量指数，存在一种趋势。这应该在专门设计用于该目的的研究中进一步研究。
