The DOI matches its Crossref record; 65 of the 65 references it cites were found in a registry or an index.
Melatonin prevents obesity through modulation of gut microbiota in mice
Abstract
Excess weight and obesity are severe public health threats worldwide. Recent evidence demonstrates that gut microbiota dysbiosis contributes to obesity and its comorbidities. The body weight‐reducing and energy balancing effects of melatonin have been reported in several studies, but to date, no investigations toward examining whether the beneficial effects of melatonin are associated with gut microbiota have been carried out. In this study, we show that melatonin reduces body weight, liver steatosis, and low‐grade inflammation as well as improving insulin resistance in high fat diet (HFD)‐fed mice. High‐throughput pyrosequencing of the 16S rRNA demonstrated that melatonin treatment significantly changed the composition of the gut microbiota in mice fed an HFD. The richness and diversity of gut microbiota were notably decreased by melatonin. HFD feeding altered 69 operational taxonomic units (OTU s) compare with a normal chow diet (NCD) group, and melatonin supplementation reversed 14 OTU s to the same configuration than those present in the NCD group, thereby impacting various functions, in particular through its ability to decrease the Firmicutes‐to‐Bacteroidetes ratio and increase the abundance of mucin‐degrading bacteria Akkermansia, which is associated with healthy mucosa. Taken together, our results suggest that melatonin may be used as a probiotic agent to reverse HFD‐induced gut microbiota dysbiosis and help us to gain a better understanding of the mechanisms governing the various melatonin beneficial effects.
Overview
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In the citing paper
“Different animal studies emphasize the beneficial effects of melatonin in the obesity management. 13-17”
From Melatonin supplementation improves glycemic hemostasis, lipid profile, and adipokine concentrations of obese women: A double-blind randomized clinical trial (2024) · cites this paper as [17]
In the citing paper
“Growing evidence showed that melatonin supplementation decreased weight in animals. 17,36-38”
From Melatonin supplementation improves glycemic hemostasis, lipid profile, and adipokine concentrations of obese women: A double-blind randomized clinical trial (2024) · cites this paper as [17]
Citations
Cites
2 retracted
Chuffa, L. G. D. A., Fioruci-Fontanelli, B. A., Mendes, L. D. O., Seiva, F. R. F., Martinez, M., Fávaro, W. J., Domeniconi, R. F., Pinheiro, P. F. F., dos Santos, L. D., & Martinez, F. E. (2015) · BMC Cancer · doi:10.1186/s12885-015-1032-4 · Cited by 100
RetractedAlonso-Chamorro, M., Collado, P. S., & González‐Gallego, J. (2006) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2006.00323.x · Cited by 86
RetractedQIIME allows analysis of high-throughput community sequencing data
Caporaso, J. G., Kuczynski, J., Stombaugh, J., Bittinger, K., Bushman, F. D., Costello, E. K., Fierer, N., Peña, A. G., Goodrich, J. K., Gordon, J. I., et al. (2010) · Nature Methods · doi:10.1038/nmeth.f.303 · Cited by 34,887
Search and clustering orders of magnitude faster than BLAST
Edgar, R. C. (2010) · Bioinformatics · doi:10.1093/bioinformatics/btq461 · Cited by 21,098
Metagenomic biomarker discovery and explanation
Segata, N., Izard, J., Waldron, L., Gevers, D., Miropolsky, L., Garrett, W. S., & Huttenhower, C. (2011) · Genome Biology · doi:10.1186/gb-2011-12-6-r60 · Cited by 16,192
FLASH: fast length adjustment of short reads to improve genome assemblies
Magoč, T., & Salzberg, S. L. (2011) · Bioinformatics · doi:10.1093/bioinformatics/btr507 · Cited by 15,366
An obesity-associated gut microbiome with increased capacity for energy harvest
Turnbaugh, P. J., Ley, R. E., Mahowald, M. A., Magrini, V., Mardis, E. R., & Gordon, J. I. (2006) · Nature · doi:10.1038/nature05414 · Cited by 12,444
Lim, S. S., Vos, T., Flaxman, A. D., Danaei, G., Shibuya, K., Adair-Rohani, H., AlMazroa, M. A., Amann, M., Anderson, H. R., Andrews, K. G., et al. (2012) · The Lancet · doi:10.1016/s0140-6736(12)61766-8 · Cited by 11,805
Human gut microbes associated with obesity
Ley, R. E., Turnbaugh, P. J., Klein, S., & Gordon, J. I. (2006) · Nature · doi:10.1038/4441022a · Cited by 8,785
Obesity alters gut microbial ecology
Ley, R. E., Bäckhed, F., Turnbaugh, P., Lozupone, C. A., Knight, R. D., & Gordon, J. I. (2005) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0504978102 · Cited by 6,176
Cani, P. D., Bibiloni, R., Knauf, C., Waget, A., Neyrinck, A. M., Delzenne, N. M., & Burcelin, R. (2008) · Diabetes · doi:10.2337/db07-1403 · Cited by 4,819
Cross-talk between Akkermansia muciniphila and intestinal epithelium controls diet-induced obesity
Everard, A., Belzer, C., Geurts, L., Ouwerkerk, J. P., Druart, C., Bindels, L. B., Guiot, Y., Derrien, M., Muccioli, G. G., Delzenne, N. M., et al. (2013) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1219451110 · Cited by 4,511
Turnbaugh, P. J., Bäckhed, F., Fulton, L., & Gordon, J. I. (2008) · Cell Host & Microbe · doi:10.1016/j.chom.2008.02.015 · Cited by 2,915
Bhaskaran, K., Douglas, I., Forbes, H., dos-Santos-Silva, I., Leon, D. A., & Smeeth, L. (2014) · The Lancet · doi:10.1016/s0140-6736(14)60892-8 · Cited by 1,707
Shin, N.-R., Lee, J.-C., Lee, H.-Y., Kim, M.-S., Whon, T. W., Lee, M.-S., & Bae, J.-W. (2014) · Gut · doi:10.1136/gutjnl-2012-303839 · Cited by 1,550
Ganoderma lucidum reduces obesity in mice by modulating the composition of the gut microbiota
Chang, C., Lin, C.-S., Lu, C., Martel, J., Ko, Y., Ojcius, D. M., Tseng, S., Wu, T.-R., Chen, Y. M., Young, J. D., et al. (2015) · Nature Communications · doi:10.1038/ncomms8489 · Cited by 1,254
Kim, K., Gu, W., Lee, I., Joh, E., & Kim, D. (2012) · PLoS ONE · doi:10.1371/journal.pone.0047713 · Cited by 1,228
Brown adipose tissue regulates glucose homeostasis and insulin sensitivity
Stanford, K. I., Middelbeek, R. J. W., Townsend, K. L., An, D., Nygaard, E. B., Hitchcox, K. M., Markan, K. R., Nakano, K., Hirshman, M. F., Tseng, Y.-H., et al. (2013) · Journal of Clinical Investigation · doi:10.1172/jci62308 · Cited by 1,180
Global burden of cancer attributable to high body-mass index in 2012: a population-based study
Arnold, M., Pandeya, N., Byrnes, G. B., Renehan, A. G., Stevens, G. A., Ezzati, M., Ferlay, J., Miranda, J. J., Romieu, I., Dikshit, R. P., et al. (2014) · The Lancet Oncology · doi:10.1016/s1470-2045(14)71123-4 · Cited by 997
National, regional, and global trends in adult overweight and obesity prevalences
Stevens, G. A., Singh, G. M., Lu, Y., Danaei, G., Lin, J. K., Finucane, M. M., Bahalim, A. N., McIntire, R. K., Gutierrez, H. R., Cowan, M. J., et al. (2012) · Population Health Metrics · doi:10.1186/1478-7954-10-22 · Cited by 967
Caesar, R., Tremaroli, V., Kovatcheva-Datchary, P., Cani, P. D., & Bäckhed, F. (2015) · Cell Metabolism · doi:10.1016/j.cmet.2015.07.026 · Cited by 960
Functions of melatonin in plants: a review
Arnao, M. B., & Hernández‐Ruíz, J. (2015) · Journal of Pineal Research · doi:10.1111/jpi.12253 · Cited by 905
The gut microbiota and obesity: from correlation to causality
Zhao, L. (2013) · Nature Reviews Microbiology · doi:10.1038/nrmicro3089 · Cited by 860
Melatonin, energy metabolism, and obesity: a review
Cipolla‐Neto, J., do Amaral, F. G., Afeche, S. C., Tan, D. X., & Reiter, R. J. (2014) · Journal of Pineal Research · doi:10.1111/jpi.12137 · Cited by 611
Melatonin: a hormone, a tissue factor, an autocoid, a paracoid, and an antioxidant vitamin
Tan, D., Manchester, L. C., Hardeland, R., López‐Burillo, S., Mayo, J. C., Sainz, R. M., & Reiter, R. J. (2002) · Journal of Pineal Research · doi:10.1034/j.1600-079x.2003.02111.x · Cited by 541
Structural resilience of the gut microbiota in adult mice under high-fat dietary perturbations
Zhang, C., Zhang, M. H., Pang, X., Zhao, Y., Wang, L., & Zhao, L. (2012) · The ISME Journal · doi:10.1038/ismej.2012.27 · Cited by 504
High-fat-diet-mediated dysbiosis promotes intestinal carcinogenesis independently of obesity
Schulz, M. D., Atay, Ç., Heringer, J., Romrig, F., Schwitalla, S., Aydın, B., Ziegler, P. K., Varga, J., Reindl, W., Pommerenke, C., et al. (2014) · Nature · doi:10.1038/nature13398 · Cited by 458
Thuy, S., Ladurner, R., Volynets, V., Wagner, S., Strahl, S., Königsrainer, A., Maier, K., Bischoff, S., & Bergheim, I. (2008) · Journal of NutriLife · doi:10.1093/jn/138.8.1452 · Cited by 432
Elevated endotoxin levels in non-alcoholic fatty liver disease
Harte, A. L., da Silva, N. F., Creely, S. J., McGee, K. C., Billyard, T., Elabd, E. M. Y., Tripathi, G., Ashour, E., Abdalla, M. S., Sharada, H. M., et al. (2010) · Journal of Inflammation · doi:10.1186/1476-9255-7-15 · Cited by 406
Microbiota depletion promotes browning of white adipose tissue and reduces obesity
Suárez-Zamorano, N., Fabbiano, S., Chevalier, C., Stojanović, O., Colin, D. J., Stevanović, A., Veyrat-Durebex, C., Tarallo, V., Rigo, D., Germain, S., et al. (2015) · Nature Medicine · doi:10.1038/nm.3994 · Cited by 403
Xiao, S., Fei, N., Pang, X., Shen, J., Wang, L., Zhang, B., Zhang, M. H., Zhang, X., Zhang, C., Li, M., et al. (2013) · FEMS Microbiology Ecology · doi:10.1111/1574-6941.12228 · Cited by 376
Self-citationTan, D. ‐., Manchester, L. C., Fuentes‐Broto, L., Paredes, S. D., & Reiter, R. J. (2010) · Obesity Reviews · doi:10.1111/j.1467-789x.2010.00756.x · Cited by 353
Geurts, L., Lazarević, V., Derrien, M., Everard, A., Roye, M. V., Knauf, C., Valet, P., Girard, M., Muccioli, G. G., François, P., et al. (2011) · Frontiers in Microbiology · doi:10.3389/fmicb.2011.00149 · Cited by 335
Melatonin Reduces Body Weight Gain in Sprague Dawley Rats with Diet-Induced Obesity
Prunet‐Marcassus, B., Desbazeille, M., Bros, A., Louche, K., Delagrange, P., Renard, P., Casteilla, L., & Pénicaud, L. (2003) · Endocrinology · doi:10.1210/en.2003-0693 · Cited by 281
Heldmaier, G., Steinlechner, S., Rafael, J., & Vsiansky, P. (1981) · Science · doi:10.1126/science.7233183 · Cited by 233
Pineal hormone melatonin oscillates also in the dinoflagellateGonyaulax polyedra
P�ggeler, B., Balzer, I., Hardeland, R., & Lerchl, A. (1991) · Die Naturwissenschaften · doi:10.1007/bf01134354 · Cited by 228
Melatonin induces browning of inguinal white adipose tissue in Zucker diabetic fatty rats
Jiménez‐Aranda, A., Fernández‐Vázquez, G., Campos, D., Tassi, M., Velasco‐Perez, L., Tan, D. X., Reiter, R. J., & Agil, A. (2013) · Journal of Pineal Research · doi:10.1111/jpi.12089 · Cited by 193
Melatonin improves glucose homeostasis in young Zucker diabetic fatty rats
Agil, A., Rosado, I., Ruiz, R., Figueroa, A., Zen, N., & Fernández‐Vázquez, G. (2012) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2011.00928.x · Cited by 169
Targeting the Microbiota to Address Diet-Induced Obesity: A Time Dependent Challenge
Clarke, S. F., Murphy, E. F., O’Sullivan, Ó., Ross, R. P., O’Toole, P. W., Shanahan, F., & Cotter, P. D. (2013) · PLoS ONE · doi:10.1371/journal.pone.0065790 · Cited by 169
Beneficial effects of melatonin on obesity and lipid profile in young Zucker diabetic fatty rats
Agil, A., Navarro‐Alarcón, M., Ruiz, R., Abuhamdah, S. M. A., El‐Mir, M., & Vázquez, G. F. (2010) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2010.00830.x · Cited by 168
Ríos-Lugo, M. J., Cano, P., Jiménez‐Ortega, V., Fernández‐Mateos, P., Scacchi, P. A., Cardinali, D. P., & Esquifino, A. I. (2010) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2010.00798.x · Cited by 168
Agil, A., Reiter, R. J., Jiménez‐Aranda, A., Arias, R. I., Navarro‐Alarcón, M., Marchal, J. A., Adem, A., & Fernández‐Vázquez, G. (2012) · Journal of Pineal Research · doi:10.1111/jpi.12012 · Cited by 161
Szewczyk‐Golec, K., Woźniak, A., & Reiter, R. J. (2015) · Journal of Pineal Research · doi:10.1111/jpi.12257 · Cited by 153
Nduhirabandi, F., Toit, E. F. D., Blackhurst, D., MARAIS, D. P., & Lochner, A. (2010) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2010.00826.x · Cited by 144
Arnold, M., Jiang, L., Stefanick, M. L., Johnson, K., Lane, D. S., LeBlanc, E. S., Prentice, R. L., Rohan, T. E., Snively, B. M., Vitolins, M. Z., et al. (2016) · PLoS Medicine · doi:10.1371/journal.pmed.1002081 · Cited by 140
Li, Z., Nickkholgh, A., Yi, X., Bruns, H., Groß, M.-L., Hoffmann, K., Mohr, E., Zorn, M., Büchler, M. W., & Schemmer, P. (2009) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2009.00672.x · Cited by 136
Melatonin stimulates Growth of Brown Adipose Tissue
Heldmaier, G., & Hoffmann, K. H. (1974) · Nature · doi:10.1038/247224a0 · Cited by 120
Global trends in the prevalence of overweight and obesity
Morgen, C. S., & Sørensen, T. I. A. (2014) · Nature Reviews Endocrinology · doi:10.1038/nrendo.2014.124 · Cited by 117
Melatonin prevents mitochondrial dysfunction and insulin resistance in rat skeletal muscle
Teodoro, B. G., Baraldi, F. G., Sampaio, I. H., Bomfim, L. H. M., Queiroz, A. L., Passos, M. A., Carneiro, E. M., Alberici, L. C., Gomis, R., Amaral, F. G., et al. (2014) · Journal of Pineal Research · doi:10.1111/jpi.12157 · Cited by 106
Melatonin and 5-methoxytryptamine in non-metazoans
Hardeland, R. (1999) · annales de biologie animale biochimie biophysique · doi:10.1051/rnd:19990311 · Cited by 104
Melatonin improves insulin sensitivity independently of weight loss in old obese rats
Zanuto, R., de Siqueira-Filho, M. A., Caperuto, L. C., Bacurau, R. F. P., Hirata, E., Garcia, R. A. P., do Amaral, F. G., Marçal, A. C., Ribeiro, L. M., Camporez, J. P., et al. (2013) · Journal of Pineal Research · doi:10.1111/jpi.12056 · Cited by 98
Melatonin reduces hepatic mitochondrial dysfunction in diabetic obese rats
Agil, A., El‐Hammadi, M. M., Jiménez‐Aranda, A., Tassi, M., Abdo, W. S., Fernández‐Vázquez, G., & Reiter, R. J. (2015) · Journal of Pineal Research · doi:10.1111/jpi.12241 · Cited by 87
Xu, P., Hong, F., Wang, J., Cong, Y., Dai, S., Wang, S., Wang, J., Jin, X., Wang, F., Liu, J., et al. (2017) · EBioMedicine · doi:10.1016/j.ebiom.2017.01.019 · Cited by 81
Self-citationCano, P., Pagano, E. S., Jiménez‐Ortega, V., Fernández‐Mateos, P., Esquifino, A. I., & Cardinali, D. P. (2014) · Journal of Pineal Research · doi:10.1111/jpi.12168 · Cited by 67
Chen, X., Zhang, C., Zhao, M., Shi, C.-E., Zhu, R.-M., Wang, H., Zhao, H., Wei, W., Li, J., & Xu, D. (2011) · Journal of Pineal Research · doi:10.1111/j.1600-079x.2011.00905.x · Cited by 64
Jiménez‐Aranda, A., Fernández‐Vázquez, G., A‐Serrano, M. M., Reiter, R. J., & Agil, A. (2014) · Journal of Pineal Research · doi:10.1111/jpi.12147 · Cited by 64
Xu, P., Dai, S., Wang, J., Zhang, J., Liu, J., Wang, F., & Zhai, Y. (2016) · Scientific Reports · doi:10.1038/srep19659 · Cited by 39
Self-citationy Aibar, M. D. M., García‐Moreno, H., González-Yanes, C., & Calvo, J. R. (2016) · Journal of Cellular Biochemistry · doi:10.1002/jcb.25491 · Cited by 36
Melatonin in the Biliary Tract and Liver: Health Implications
Reiter, R. J., Rosales‐Corral, S., Manchester, L. C., Liu, X., & Tan, D. (2014) · Current Pharmaceutical Design · doi:10.2174/1381612819666131119105826 · Cited by 34
Effects of Short Photoperiod and Melatonin Treatment on Thermogenesis in the Syrian Hamster
Viswanathan, M. N., Hissa, R., & George, J. C. (1986) · Journal of Pineal Research · doi:10.1111/j.1600-079x.1986.tb00754.x · Cited by 32
Xiao, L., Wang, J., Li, J., Chen, X., Xu, P., Sun, S., He, D., Cong, Y., & Zhai, Y. (2014) · American Journal of Physiology-Cell Physiology · doi:10.1152/ajpcell.00091.2014 · Cited by 30
Self-citationHoltorf, A., Heldmaier, G., Thiele, G., & Steinlechner, S. (1985) · Journal of Pineal Research · doi:10.1111/j.1600-079x.1985.tb00719.x · Cited by 30
Jiang, Y., Xu, Y., Bi, Y., Wang, L., Zhang, M., Zhou, M., Yichong, L., Xu, M., Lu, J., Wang, T., et al. (2015) · The Lancet · doi:10.1016/s0140-6736(15)00658-3 · Cited by 26
Brzozowski, T., & Jaworek, J. M. (2014) · Current Pharmaceutical Design · doi:10.2174/1381612819666131119111201 · Cited by 15
Experimental Helicobacter marmotae infection in A/J mice causes enterohepatic disease
Patterson, M. M., Rogers, A. B., & Fox, J. G. (2010) · Journal of Medical Microbiology · doi:10.1099/jmm.0.020479-0 · Cited by 12
Research works printed but not linked: 1
- Sajan MP, 2008, Activation of sterol receptor element binding protein‐1c and nfkb by atypical protein kinase c in liver mediates lipid abnormalities and insulin resistance in murine obesity models, Diabetes, 57, A376
Cited by
Sorted by citations
Melatonin as a mitochondria-targeted antioxidant: one of evolution's best ideas
Reiter, R. J., Rosales-Corral, S., Tan, D. X., Jou, M. J., Galano, A., & Xu, B. (2017) · Cellular and Molecular Life Sciences · doi:10.1007/s00018-017-2609-7 · Cited by 558
Probiotics improve gut microbiota dysbiosis in obese mice fed a high-fat or high-sucrose diet
Kong, C., Gao, R., Yan, X., Huang, L., & Qin, H. (2018) · Nutrition · doi:10.1016/j.nut.2018.10.002 · Cited by 497
Melatonin reprogramming of gut microbiota improves lipid dysmetabolism in high‐fat diet‐fed mice
Yin, J., Li, Y., Han, H. L., Chen, S., Gao, J., Liu, G., Wu, X., Deng, J., Yu, Q., Huang, X., et al. (2018) · Journal of Pineal Research · doi:10.1111/jpi.12524 · Cited by 387
Resveratrol-induced gut microbiota reduces obesity in high-fat diet-fed mice
Wang, P., Li, D., Ke, W., Liang, D., Hu, X., & Chen, F. (2020) · International Journal of Obesity · doi:10.1038/s41366-019-0332-1 · Cited by 301
Role of melatonin in sleep deprivation‐induced intestinal barrier dysfunction in mice
Gao, T., Wang, Z., Dong, Y., Cao, J., Lin, R., Wang, X., Yu, Z., & Chen, Y. (2019) · Journal of Pineal Research · doi:10.1111/jpi.12574 · Cited by 301
Metadata
- Authors
- Xu, P., Wang, J., Hong, F., Wang, S., Jin, X., Xue, T., Jia, L., & Zhai, Y.
- Affiliations
- Beijing Normal University (CN)
- Beijing Key Laboratory of Gene Resource and Molecular Development College of Life Sciences Beijing Normal University Beijing China
- Corresponding author
- Zhai, Yonggong
- Venue
- Journal of Pineal Research
- Publisher
- Wiley
- Published
- 2017-03-10
- Volume
- 62
- Issue
- 4
- ISSN
- 0742-3098 (ISSN-L)
- 1600-079X
- OpenAlex
- W2587996254
- Cited by
- 281
- References
- 65
- Citations by year
- 2026: 9 · 2025: 17 · 2024: 28 · 2023: 36 · 2022: 48 · 2021: 51 · 2020: 36 · 2019: 27 · 2018: 21 · 2017: 8
- FWCI
- 10.28
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Journal of Pineal Research (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Natural Science Foundation of China (31571164, 31271207)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Regulation of Appetite and Obesity
- Keywords
- melatonin, obesity, gut microbiota, dysbiosis, high-fat diet, body weight, hepatic steatosis, insulin resistance, low-grade inflammation, Akkermansia, Firmicutes/Bacteroidetes ratio, mucin-degrading bacteria, probiotics
- MeSH terms
- Firmicutes, Bacillota, Gastrointestinal Microbiome, Animals, Central Nervous System Depressants, Fatty Liver, Inflammation, Insulin Resistance, Male, Melatonin, Mice, Inbred C57BL, Obesity, Blotting, Western, Weight Gain, Glucose Intolerance, Probiotics, Bacteroidetes, Mice, Diet, High-Fat
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review