Bifidobacterium pseudocatenulatum-Mediated Bile Acid Metabolism to Prevent Rheumatoid Arthritis via the Gut–Joint Axis

Round 1

Reviewer 1 Report

Authors reported that Bifidobacterium pseudocatenulatum administration in a prophylactic setting can help in decreasing the onset and severity of RA in a CIA mouse model. This effect is metabolite mediated (Bile Acids) and TGR5 mediated. This signaling modulates host immunity.

Data are overall convincing, however some modifications should be provided in order to improve the quality and clarity of the manuscript.

Figure 1L: Add the bifido relative abundance in Healthy Controls

Fig 2G: Since in panel E there is several diseases depicted, in panel G, the word “disease” should be replaced by RA to gain in clarity.

Fig3A: Please specify the time point of blood collection for immune cell analyses.

Fig 3B: There is no stat depicted, but in the text (line 288) it is written "significantly". please clarify

Fig 3N: due to the low cell number the illustrative dot plot are not so convincing. Please replace the density plots by big dot plots. It may help to visualize the positive cells.

Fig4: The panels A and C are really convincing. However, the B is not. In addition, the panel D clearly show that prophylactic Bifido restore ZO-1 while therapeutic did not. However, in the panel E, the results seems equivalent between the 2 conditions. Could you elaborate on that ? The conclusions in the text are based on panel A and C but we can’t conclude that there is an impact at the protein level (due to panel B, and E)

Fig 4 J-K: 16S sequencing. Could you add the control groups to see the impact of bifido supplementation on microbiota?

Fig sup 2B: I agree that the bifido treated mice (pre and post CIA induction) are close to the control compared to CIA alone. In the text, it is suggested that only prophylactic treatment is close to the control. Please modify that.

Fig 6A: please specifiy where and when the cytokine have been quantified?

Fig 6C: Why authors used anova instead of t-test as in all other figures. Usually, anova with only 3 points are considered unaccurate.

Fig 6J: Please specify in the text why DCA or LCA treatments were not administrated at the same time points as bifido gavages.

Fig 6K to N: please remove the ns for clarity and specify within the legend that when unindicated, the stat are ns.

Line 85: "of" missing

Line 226-228: The sentence is unclear. The conclusion seems inverted regarding the observations made in Fig 1G-L

Line 262: Please clarify that it is intestinal epithelial cell LINES to avoid any confusion.

The word "in vitro" should be in italics (several occurrences along the text)

Line 341: to investigate without d

Line 347 and 350: Th17 instead of T17

Line 439: Since it is just based on observations and correlation, please replace is attributed by might be attributed.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 2 Report

In the article "Bifidobacterium pseudocatenulatum-mediated bile acid metabolism to prevent rheumatoid arthritis via the gut-joint axis," the authors tested the impact of probiotic intervention on BA and intestinal microbiota composition.

The introduction should be shortened.

It is necessary to check the English language.

There are sentences in the results that are part of the methodology and should not be there.

The authors should mention the challenges and limitations of the study.

The manuscript should be more organized.

Figures should be organized and organized in the right places in the manuscript; authors should review if indeed all figures are necessary.

Not all abbreviations are explained.

Lines 259, 556 do not have italics in the names of bacteria; authors should revise the whole article.

Lines 521-522: There are repeated results in the discussion, figures as above (is it necessary?), the discussion could be more developed.

550-551 "Therapeutic strategies targeting the gut microbiota and the gut-joint axis have been 550 improved since the 1940s" - I think this sentence is not necessary.

Author Response

Please see the attachment.

Author Response File: Author Response.doc