Review for 10.1186/s12876-020-01194-2 (2020)

Reviewer’s report
Title: Fructo-Oligosaccharides Ameliorate Steatohepatitis, Visceral Adiposity, and Associated
Chronic Inflammation via Increased Production of Short-Chain Fatty Acids in a Mouse Model of
Non-alcoholic Steatohepatitis
Version: 0 Date: 09 Dec 2019
Reviewer: Annette Brandt
Reviewer's report:
In this manuscript by Atsuko Takai et al. the authors demonstrate that fructo-oligosaccharides (FOS)
are able to ameliorate NASH in a monosodium glutamate (MSG)-induced obesity model. This is an
interesting study and the data support the authors conclusions, however, there are some questions that
needs to be addressed:
Major comments:
To characterize the used MSG mouse model in more detail, is this mouse model comparable to ob/ob
model? Do these mice similar to ob/ob mice have an enormous increased food intake? Moreover, the
authors mentioning that the MCD-NASH model (which was used by the authors in a previous study) is
not exhibiting obesity or insulin resistance, explaining the choice of the MSG-induced obesity and
NASH model. To characterize this mouse model in more detail, do these mice also develop insulin
resistance/altered glucose metabolism? (e.g. altered fasting blood glucose?) Is FOS-treatment in this
study affecting this? 
Are  there  mice  also  treated  with  FOS  without  receiving  MSG-injection?  Were  there  any effects
compared to control mice?
The authors mentioning macroscopic fecal findings in figure legend of additional file 1, but it seems,
that this is missing in the figure? 
It  should  be  explained  in  more  detail,  how  the  embedded  epididymal  fat  was  evaluated
histopathologically to evaluate the size/structure of the fat.
Minor comments:
Labeling of the figures should be uniform, e.g. all of them should be organized using small letters
(figure 3 and 5 dot not have) and this labeling should also appear in the figure legends.
Line 255: What do the authors mean with „…Displayed a better bacterial balance"? This should be
explained.
Was the liver:body weight ratio evaluated?
p-values for bacterial composition of feces are missing (line 248…)
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
No
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you recommend an
additional statistical review?
If an additional statistical review is recommended, please specify what aspects require further
assessment in your comments to the editors.
I am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
Declaration of competing interests
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or has applied for patents relating to the content of the manuscript?
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If your reply is yes to any, please give details below.
None
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