Table_3_Colonization of Supplemented Bifidobacterium breve M-16V in Low Birth Weight Infants and Its Effects on Their Gut Microbiota Weeks Post-administration.docx

The colonization and persistence of probiotics introduced into the adult human gut appears to be limited. It is uncertain, however, whether probiotics can successfully colonize the intestinal tracts of full-term and premature infants. In this study, we investigated the colonization and the effect of oral supplementation with Bifidobacterium breve M-16V on the gut microbiota of low birth weight (LBW) infants. A total of 22 LBW infants (12 infants in the M-16V group and 10 infants in the control group) were enrolled. B. breve M-16V was administrated to LBW infants in the M-16V group from birth until hospital discharge. Fecal samples were collected from each subject at weeks (3.7–9.3 weeks in the M-16V group and 2.1–6.1 weeks in the control group) after discharge. qPCR analysis showed that the administrated strain was detected in 83.3% of fecal samples in the M-16V group (at log10 8.33 ± 0.99 cell numbers per gram of wet feces), suggesting that this strain colonized most of the infants beyond several weeks post-administration. Fecal microbiota analysis by 16S rRNA gene sequencing showed that the abundance of Actinobacteria was significantly higher (P < 0.01), whereas that of Proteobacteria was significantly lower (P < 0.001) in the M-16V group as compared with the control group. Notably, the levels of the administrated strain and indigenous Bifidobacterium bacteria were both significantly higher in the M-16V group than in the control group. Our findings suggest that oral administration of B. breve M-16V led to engraftment for at least several weeks post-administration and we observed a potential overall improvement in microbiota formation in the LBW infants’ guts.

外源性引入成人肠道的益生菌，其定植与留存能力往往较为有限。然而，益生菌能否成功定植足月与早产婴儿的肠道，目前尚无定论。本研究针对低出生体重（low birth weight, LBW）婴儿的肠道定植情况，以及口服补充短双歧杆菌（Bifidobacterium breve）M-16V对其肠道菌群的影响展开探究。本研究共纳入22名LBW婴儿，其中M-16V组12名，对照组10名。M-16V组的LBW婴儿自出生起至出院期间，均接受短双歧杆菌M-16V口服干预。研究人员于受试者出院后第3.7~9.3周（M-16V组）及第2.1~6.1周（对照组）采集粪便样本。实时荧光定量PCR（quantitative PCR, qPCR）分析结果显示，M-16V组83.3%的粪便样本中可检测到该口服菌株，其含量为每克湿粪便log₁₀8.33±0.99个菌体，表明该菌株在给药数周后仍可在多数婴儿肠道中定植。通过16S rRNA基因测序开展的粪便菌群分析结果显示，与对照组相比，M-16V组的放线菌门（Actinobacteria）丰度显著升高（P<0.01），而变形菌门（Proteobacteria）丰度则显著降低（P<0.001）。值得注意的是，M-16V组的口服定植菌株与本土双歧杆菌（Bifidobacterium）的含量均显著高于对照组。本研究结果表明，口服短双歧杆菌M-16V可使菌株在婴儿肠道中定植至少数周，且LBW婴儿的肠道菌群构建存在整体改善的潜力。