Review Reports

Round 1

Reviewer 1 Report

Dear Authors,

Overall the manuscript is well written and the study well designed. I want to suggest to improve the discussion a little bit by taking insight into two interesting manuscripts:

1. “Montefusco et al, Journal of Endocrinol Invest, 2021“, where authors show that fasting insulinemia and HOMA-IR are positively correlated with Mediterranean, polyphenol- and fiber-rich diet.
2. “D’Addio F et al, Cell Stem Cell, 2015“ where authors show that gut microbiota composition and function are influenced by physical activity, metabolic diseases (like obesity and diabetes), diet interventions but also other circulating factors (antioxidants, cytokines, IGF-I, IGFBP3).

Author Response

Reviewer 1

Overall the manuscript is well written and the study well designed. I want to suggest to improve the discussion a little bit by taking insight into two interesting manuscripts:

1. “Montefusco et al, Journal of Endocrinol Invest, 2021“, where authors show that fasting insulinemia and HOMA-IR are positively correlated with Mediterranean, polyphenol- and fiber-rich diet.
2. “D’Addio F et al, Cell Stem Cell, 2015“ where authors show that gut microbiota composition and function are influenced by physical activity, metabolic diseases (like obesity and diabetes), diet interventions but also other circulating factors (antioxidants, cytokines, IGF-I, IGFBP3).

We thank the reviewer for his/her comment. The two references have been added to the manuscript (line 448 and line 532).

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors present a well-written study describing the effect of high-intensity interval exercise with and without the supplementation of the dietary complex polyphenol supplementation TOTUM-63. The authors also examine and correlate the microbiota composition with the treatments. This is an interesting study and although the effects of polyphenols and HIIT on the regulation of adiposity, glycemic control, and gut microbiota composition have been independently investigated in the past, this study highlights the interaction of these two interventions. 

The authors observed a significantly increased mortality in groups receiving T63 during the period of intervention. Did the authors determine the cause of death? Did the authors perform routine histology and post-mortem examination of organs from the dead rats?

The effect of the HFD on obesity induction was significant, however, HFD rats maintained normoglycemia. Can the authors discuss why this might have been the case, (HFD composition, duration of HFD feeding?)

The authors should give exact details of how food consumption and its conversion of kCal was performed in the methods section.

The claim of normalization of glycemic control can be made more convincing by showing the "asterisks" for the posthoc comparisons for Fig4D for individual groups (at least for the HIIT + T63 versus HFD).  A brief description of the statistical ANOVA test and abbreviations (G, T, G x T) used in Fig.4D must be included in the figure description but are missing. 

The blot in Fig.5A is not representative as it shows the highest levels in the T63 group. A more representative blot is necessary.

 

 

 

Author Response

Reviewer 2

The authors present a well-written study describing the effect of high-intensity interval exercise with and without the supplementation of the dietary complex polyphenol supplementation TOTUM-63. The authors also examine and correlate the microbiota composition with the treatments. This is an interesting study and although the effects of polyphenols and HIIT on the regulation of adiposity, glycemic control, and gut microbiota composition have been independently investigated in the past, this study highlights the interaction of these two interventions. 

We thank the reviewer for his/her comments.

The authors observed a significantly increased mortality in groups receiving T63 during the period of intervention. Did the authors determine the cause of death? Did the authors perform routine histology and post-mortem examination of organs from the dead rats?

As mentioned in the legend to Figure 1, rats died during glucose gavage due to intubation mishandling. For this reason, we did not perform histology and post-mortem examination of organs.

The effect of the HFD on obesity induction was significant, however, HFD rats maintained normoglycemia. Can the authors discuss why this might have been the case, (HFD composition, duration of HFD feeding?)

Wistar rats are considered to be an appropriate model for HF diet-induced obesity. Furthermore, HFD-induced metabolic effects is more pronounced in Wistar rats than in other models, such  as Sprague Dawley (Marques et al., 2015). Metabolic alterations are the ultimate consequences of HF diet. First, energy excess increases the total fat mass, including the ectopic fat mass, leading then to an impairment of insulin signaling and glucose tolerance. Thus, metabolic disturbances depend on this time course. In our study, we only observed a moderate fat mass gain after HF diet and this may explain why rats were still normoglycemic. This result has been already described in other studies performed with the same model (Gerbaix et al. 2012). In fact, our diet was a moderate HF diet. With HF diets higher in fat (~60%) or when fructose is added to saturated fats, the effects are faster. This is similar to what observed in humans. It takes time to people with obesity to develop diabetes and the period of prediabetes can last several years (Philips, 2017).

The authors should give exact details of how food consumption and its conversion of kCal was performed in the methods section.

This precision has been added in the methodology section (line 133).

The claim of normalization of glycemic control can be made more convincing by showing the "asterisks" for the posthoc comparisons for Fig4D for individual groups (at least for the HIIT + T63 versus HFD).  A brief description of the statistical ANOVA test and abbreviations (G, T, G x T) used in Fig.4D must be included in the figure description but are missing. 

The precisions have been added in Fig.4D.

The statistical abbreviations (G, T, G ´ T) significations have been included in Fig.4 and in all figures when needed.

The blot in Fig.5A is not representative as it shows the highest levels in the T63 group. A more representative blot is necessary.

The blot has been changed in Fig.5A

 

 

Author Response File: Author Response.pdf