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ment; twelve subjects were scanned at baseline and endpoint for L. reuteri treatment; and twelve subjects underwent scans at baseline and endpoint for control.

No treatment effect was observed at endpoint in total lean mass and total fat mass. However, over the study period, total fat mass was decreased (P=0.0158) by 3% from baseline in response to L. fermentum treatment, while L. reuteri feeding reduced (P=0.0211) fat mass by 4% from baseline to endpoint. In addition, total fat mass was observed to be decreased (P=0.0127) by 1% from baseline with control. These changes occurred despite no statistically significant shift in body weights across treatments.

Additional analysis was performed on a subset of data where values outside the range of two standard deviations were removed form the original data set. No treatment effect was observed at endpoint in total lean mass and total fat mass using ANOVA.

Microbial abundance in response to treatments

The sub-study for the microbial composition of human stool samples was conducted as a blinded study, in which the investigators were not knowledgeable of the order of the treatments.. The only designation that was available was O, M, or N. Once the RT-PCR data had been compiled it became fairly obvious that “O” was the control. At this point the treatments were unblinded and treatment designations were as follows:

O = control

M = Lactobacillus fermentum

N = Lactobacillus reuteri

The quantification of the RT-PCR data is provided relative to the control treatment. As discussed in the methods we typically use an internal control rather than an external control. The reason for this is that the RT-PCR data are based on the efficiency of the PCR reaction. In gut samples, as with many environmental samples, there is always contamination of the DNA extract with food components which result in a decreased efficiency of the PCR reaction. Thus, if one does not take this inefficiency into account erroneous results can be obtained. The efficiency with an external standard is always high.

There was a highly significant effect for Lactobacillus (P = 0.008), when the control (O) was compared to M and N. This was to be expected because both probiotic treatments, M and N, were Lactobacillus containing yogurts.

The feeding of Lactobacillus exerted a synergistic effect (P = 0.038), directly or indirectly, on the Clostridium cluster IV group in the gut. Clostridium cluster IV contains a large number of butyrate producing bacteria (Collins et al., 1994). Butyrate formation in the gut is considered an important health indicator and dietary interventions that result in increased butyrate is beneficial (Flint et al., 2008). Many of the Clostridium cluster IV bacteria are able to ferment indigestible complex polysaccharides like inulin, oligofructose, xylooligosaccharides, and other polysaccharides that pass to the hind-gut undigested. This investigator was not provided with information as to other components of the yogurt, however, it can be speculated that either there were indigestible polysaccharides in the yogurt, or Lactobacillus directly influenced the Clostridium cluster IV cluste本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。