Guillermo Meléndez

Dr. Guillermo Meléndez

orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 February 2022 in Microorganisms
Verified
Journal Article
Open access
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LMLucia Mendez
Lucia Mendez
NBNallely Bueno-Hernández
Nallely Bueno-Hernández
MCMiguel A. Cid-Soto
Miguel A. Cid-Soto
KLKaren L. De León
Karen L. De León
Viridiana Montsserrat Mendoza-MartínezViridiana Montsserrat Mendoza-Martínez
Viridiana Montsserrat Mendoza-Martínez
GEGalileo Escobedo
Galileo Escobedo
Sucralose consumption alters microbiome and carbohydrate metabolism in mouse models. However, there are no conclusive studies in humans. Our goals were to examine the effect of sucralose consumption on the intestinal abundance of bacterial species belonging to Actinobacteria, Bacteroidetes, and Firmicutes and explore potential associations between microbiome profiles and glucose and insulin blood levels in healthy young adults. In this open-label clinical trial, volunteers randomly drank water, as a control (n = 20), or 48 mg sucralose (n = 20), every day for ten weeks. At the beginning and the end of the study, participants were subjected to an oral glucose tolerance test (OGTT) to measure serum glucose and insulin every 15 min for 3 h and provided fecal samples to assess gut microbiota using a quantitative polymerase chain reaction. Sucralose intake altered the abundance of Firmicutes without affecting Actinobacteria or Bacteroidetes. Two-way ANOVA revealed that volunteers drinking sucralose for ten weeks showed a 3-fold increase in Blautia coccoides and a 0.66-fold decrease in Lactobacillus acidophilus compared to the controls. Sucralose consumption increased serum insulin and the area under the glucose curve compared to water. Long-term sucralose ingestion induces gut dysbiosis associated with altered insulin and glucose levels during an OGTT.

1 September 2014 in International Journal of Surgery
Verified
Journal Article
Closed access
YRYanelli Rodríguez-Carmona
Yanelli Rodríguez-Carmona
FLFrancisco J. López-Alavez
Francisco J. López-Alavez
AGAlejandro G. González-Garay
Alejandro G. González-Garay
CSCecilia Solís-Galicia
Cecilia Solís-Galicia
GMGuillermo Meléndez
Guillermo Meléndez
ASAurora E Serralde-Zúñiga
Aurora E Serralde-Zúñiga
Bone regulation system may be affected after bariatric surgeries, but procedures impact differently to bone mineral density (BMD) and measures restraining bone loss are frequently neglected until clinical consequences become manifest. This is a systematic review aimed to elucidate whether BMD loss is comparable after different bariatric surgeries. A search of morbid obese adults, undergone to bariatric surgery, with BMD measured by dual-energy X-ray absorptiometry at baseline and after surgery studies was performed in several databases. Studies were assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement and COCHRANE Risk of Bias tool. The random model was selected for meta-analysis; heterogeneity was analyzed with T(2), inconsistency (I(2) > 50%) and Chi(2) (p < 0.10). Level of evidence and strength of recommendations were summarized using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE System). Twelve studies met the selection criteria. After one year, reduction in total BMD in patients with mixed surgical procedures was significant: -0.03 g/cm(2) (CI 95% 0.00 to -0.06, p < 0.05). BMD was reduced by -0.12 g/cm(2) (CI 95% -0.10 to -0.15, p < 0.001) in the hip, -0.07 g/cm(2) (CI 95% -0.03 to -0.11, p < 0.001) in the column, and -0.03 g/cm(2) (IC 95% -0.02 to -0.04, p < 0.001) in the forearm, but not in restrictive surgeries. Studies included showed high heterogeneity and low quality of evidence. Patients undergone to mixed bariatric surgery had significant higher BMD deterioration as demonstrated in this review, suggesting that more attention for preventing fractures is required.

3 September 2018 in Journal of Translational Medicine
Verified
Journal Article
Open access
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CRChristian Ramos-Peñafiel
Christian Ramos-Peñafiel
IOIrma Olarte
Irma Olarte
RMRafael Cerón Maldonado
Rafael Cerón Maldonado
EREtta Rozen-Fuller
Etta Rozen-Fuller
JKJuan Julio Kassack-Ipiña
Juan Julio Kassack-Ipiña
ATADOLFO MARTINEZ TOVAR
ADOLFO MARTINEZ TOVAR
In acute lymphoblastic leukemia (ALL), high ABCB1 gene expression has been associated with treatment resistance, which affects patient prognosis. Many preclinical reports and retrospective population studies have shown an anti-cancer effect of metformin. Therefore, the objective of this study was to assess the effect of metformin on the treatment regimen in patients with ALL who exhibited high levels of ABCB1 gene expression and to determine its impact on overall survival. A total of 102 patients with ALL were recruited; one group (n = 26) received metformin, and the other received chemotherapy (n = 76). Measurement of ABCB1 transcript expression was performed using qRT-PCR prior to treatment initiation. Survival analysis was performed using Kaplan–Meier curves. The impact of both the type of treatment and the level of expression on the response (remission or relapse) was analyzed by calculating the odds ratio. The survival of patients with high ABCB1 expression was lower than those with low or absent ABCB1 gene expression (p = 0.030). In the individual analysis, we identified a benefit to adding metformin in the group of patients with high ABCB1 gene expression (p = 0.025). In the metformin user group, the drug acted as a protective factor against both therapeutic failure (odds ratio [OR] 0.07, 95% confidence interval [CI] 0.0037–1.53) and early relapse (OR 0.05, 95% CI 0.0028–1.153). The combined use of metformin with chemotherapy is effective in patients with elevated levels of ABCB1 gene expression. Trial registration NCT 03118128: NCT

5 March 2022 in Nutrients
Verified
Journal Article
Open access
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Viridiana Montsserrat Mendoza-MartínezViridiana Montsserrat Mendoza-Martínez
Viridiana Montsserrat Mendoza-Martínez
MZMónica Rocío Zavala-Solares
Mónica Rocío Zavala-Solares
AEAranza-Jhosadara Espinosa-Flores
Aranza-Jhosadara Espinosa-Flores
KLKaren Lorena León-Barrera
Karen Lorena León-Barrera
RARaúl Alcántara-Suárez
Raúl Alcántara-Suárez
NBNallely Bueno-Hernández
Nallely Bueno-Hernández
Background: A diet containing non-caloric sweeteners (NCS) could reduce calorie intake; conversely, some animal studies suggest that NCS consumption may increase functional gastrointestinal disorder symptoms (FGDs). This study aimed to compare the effect of consuming a diet containing NCS (c-NCS) versus a non-caloric sweetener-free diet (NCS-f) on FGDs. Methods: We conducted a randomized, controlled, parallel-group study using two different diets for five weeks: the c-NCS diet contained 50–100 mg/day NCS, whereas the NCS-f diet had less than 10 mg/day NCS. At the beginning of the study (PreTx) and at the end (PostTx), we assessed FGDs, dietary intake, and NCS consumption. Results: The percentage of participants with diarrhea (PreTx = 19% vs. PstTx = 56%; p = 0.02), post-prandial discomfort (PreTx = 9% vs. PstTx = 39%; p = 0.02), constipation (PreTx = 30% vs. PostTx = 56%; p < 0.01), and burning (PreTx = 13% vs. PostTx = 33%; p < 0.01) increased in the c-NCS diet group. Conversely, abdominal pain (PreTx = 15% vs. PostTx = 3%; p = 0.04), post-prandial discomfort (PreTx = 26% vs. PostTx = 6%; p = 0.02), burning (PreTx = 15% vs. PostTx = 0%; p = 0.02), early satiety (PreTx = 18% vs. PostTx = 3%; p < 0.01), and epigastric pain (PreTx = 38% vs. PostTx = 3%; p < 0.01) decreased in the NCS-f diet group. Conclusion: A c-NCS diet is associated with increased FGDs, including diarrhea, post-prandial discomfort, constipation, and burning or retrosternal pain. The NCS-f diet also decreased FGDs, as well as abdominal pain, post-prandial discomfort, burning or retrosternal pain, early satiety, and epigastric pain.

3 April 2018 in Journal of Immunology Research
Verified
Journal Article
Open access
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Johanna GrünJohanna Grün
Johanna Grün
Aarón N. Manjarrez-ReynaAarón N. Manjarrez-Reyna
Aarón N. Manjarrez-Reyna
AGAngélica Y. Gómez-Arauz
Angélica Y. Gómez-Arauz
SONIA LEON-CABRERASONIA LEON-CABRERA
SONIA LEON-CABRERA
FRFelix Rückert
Felix Rückert
GEGalileo Escobedo
Galileo Escobedo
The effect of metabolic syndrome on human monocyte subpopulations has not yet been studied. Our main goal was to examine monocyte subpopulations in metabolic syndrome patients, while also identifying the risk factors that could directly influence these cells. Eighty-six subjects were divided into metabolic syndrome patients and controls. Monocyte subpopulations were quantified by flow cytometry, and interleukin- (IL-) 1β secretion levels were measured by ELISA. Primary human monocytes were cultured in low or elevated concentrations of high-density lipoprotein (HDL) and stimulated with lipopolysaccharide (LPS). The nonclassical monocyte (NCM) percentage was significantly increased in metabolic syndrome patients as compared to controls, whereas classical monocytes (CM) were reduced. Among all metabolic syndrome risk factors, HDL reduction exhibited the most important correlation with monocyte subpopulations and then was studied in vitro. Low HDL concentration reduced the CM percentage, whereas it increased the NCM percentage and IL-1β secretion in LPS-treated monocytes. The LPS effect was abolished when monocytes were cultured in elevated HDL concentrations. Concurring with in vitro results, IL-1β serum values significantly increased in metabolic syndrome patients with low HDL levels as compared to metabolic syndrome patients without HDL reduction. Our data demonstrate that HDL directly modulates monocyte subpopulations in metabolic syndrome.

28 April 2019 in Journal of Immunology Research
Verified
Journal Article
Open access
PDF file
AGAngélica Y. Gómez-Arauz
Angélica Y. Gómez-Arauz
NBNallely Bueno-Hernández
Nallely Bueno-Hernández
LPLeon F. Palomera
Leon F. Palomera
RARaúl Alcántara-Suárez
Raúl Alcántara-Suárez
KLKaren L. De León
Karen L. De León
GMGuillermo Meléndez
Guillermo Meléndez
Sucralose is a noncaloric artificial sweetener that is widely consumed worldwide and has been associated with alteration in glucose and insulin homeostasis. Unbalance in monocyte subpopulations expressing CD11c and CD206 hallmarks metabolic dysfunction but has not yet been studied in response to sucralose. Our goal was to examine the effect of a single sucralose sip on serum insulin and blood glucose and the percentages of classical, intermediate, and nonclassical monocytes in healthy young adults subjected to an oral glucose tolerance test (OGTT). This study was a randomized, placebo-controlled clinical trial. Volunteers randomly received 60 mL water as placebo (n=20) or 48 mg sucralose dissolved in 60 mL water (n=25), fifteen minutes prior to an OGTT. Blood samples were individually drawn every 15 minutes for 180 minutes for quantifying glucose and insulin concentrations. Monocyte subsets expressing CD11c and CD206 were measured at -15 and 180 minutes by flow cytometry. As compared to controls, volunteers receiving sucralose exhibited significant increases in serum insulin at 30, 45, and 180 minutes, whereas blood glucose values showed no significant differences. Sucralose consumption caused a significant 7% increase in classical monocytes and 63% decrease in nonclassical monocytes with respect to placebo controls. Pearson’s correlation models revealed a strong association of insulin with sucralose-induced monocyte subpopulation unbalance whereas glucose values did not show significant correlations. Sucralose ingestion decreased CD11c expression in all monocyte subsets and reduced CD206 expression in nonclassical monocytes suggesting that sucralose does not only unbalance monocyte subpopulations but also alter their expression pattern of cell surface molecules. This work demonstrates for the first time that a 48 mg sucralose sip increases serum insulin and unbalances monocyte subpopulations expressing CD11c and CD206 in noninsulin-resistant healthy young adults subjected to an OGTT. The apparently innocuous consumption of sucralose should be reexamined in light of these results.