Time-restricted Feeding Group Research Articles

Serum Extracellular Vesicles Reveal Metabolic Responses to Time-Restricted Feeding in High Fat Diet-Induced Obesity in Male Mice.

Extracellular vesicle (EV) secretion and cargo composition are dysregulated in metabolic diseases. This study aimed to identify changes in the EV size profile and protein cargoes in diet-induced obesity following time-restricted feeding (TRF) and to establish the role of EVs in obesity-related metabolic responses. Mice were fed a high-fat diet (HFD) for 18 weeks prior to being placed either ad libitum or a time-restricted feeding for an additional 10 weeks. Mice on a normal chow ad libitum served as the control. The TRF group had food available for 10 hours and fasted for 14 hours per day. The serum EV size profile and amount displayed sex- and age-dependent changes in HFD-induced obesity, with age reducing EV amounts. HFD decreased small EV populations and increased larger EV populations, while TRF reversed these changes. Quantitative proteomic analysis showed that the abundance and composition of EV proteins changed in response to both acute stimulation with lipopolysaccharides (LPS) and HFD. Gene ontology analysis identified specific sets of EV proteins and their involved biological processes, reflecting the effect of LPS and HFD, as well as the reversal effect of TRF on metabolic and inflammatory pathways. EV proteins altered by HFD and those reversed by TRF had low protein overlap but significant functional overlap in biological processes. TRF activated the PPAR signaling pathway and the AKT-mTOR signaling pathway. The most significant impacts of HFD and TRF were observed on lipoprotein and carbohydrate metabolism, complement system, and neutrophil degranulation. The reversal effect of TRF on the complement system was pathway-specific, significantly activating the lectin complement pathway and restoring neutrophil degranulation. Our data indicate that EVs are involved in diet-induced metabolic and inflammatory responses. Different EV populations may carry distinct sets of proteins involved in specific biological processes, thereby regulating diverse metabolic pathways efficiently.

Time-restricted feeding relieves high temperature-induced impairment on meat quality by activating the Nrf2/HO-1 pathway, modification of muscle fiber composition, and enriching the polyunsaturated fatty acids in pigs.

To assess the effects of a time-restricted feeding (TRF) regimen on meat quality of pigs exposed to high ambient temperature, a two-month feeding and heat treatment (HT) trial was conducted using a 2 × 2 factorial design. A total of 24 growing pigs (11.0 ± 1.9kg) were randomly divided into four groups: thermal neutral group (NT, 24 ± 3°C), HT group (exposed to a high temperature at 35 ± 2°C from 11:00 to 15:00), TRF group and HT + TRF group (HT and TRF co-treatment group, n = 6 for each group). Pigs in TRF groups got access to feed within 5h from 9:00 to14:00, while the others were fed at 6:00, 11:30, and 16:00. All pigs received the same diet during the trail. The results showed that HT increased the drip loss, shear force, lightness, and malondialdehyde production in Longissimus thoracis et lumborum (LTL) muscle. TRF reversely reduced the shear force and drip loss, accompanied by decreased intramuscular fat and increased moisture content. Enhanced fiber transformation from type 1 to type 2b and down-regulated expression of muscle growth-related genes were observed by HT, while TRF suppressed the fiber transformation and expression of muscle atrophy-related genes. Furthermore, TRF restored the diminished protein expressions of Nrf2 and HO-1 in LTL muscle by chronic HT. Accumulation of HSP70 in muscle of HT group was reduced by treatment of TRF. HT declined the expression of vital genes involved in fatty acids poly-desaturation and the proportion of (polyunsaturated fatty acids) PUFAs, mainly omega-6 in LTL muscle, while TRF group promoted the expression of poly-desaturation pathway and displayed the highest proportion of PUFAs. These results demonstrated that TRF relieved the chronic high temperature affected meat quality by the restored expression of Nrf2/HO-1 anti-oxidative cascade, modified muscle fiber composition, and enriched PUFAs in LTL muscle.

Abstract P175: The Effect of TRF on Hypertension Development in Male Dahl Salt-Sensitive Rats

Time restricted feeding (TRF), or food consumption restricted to <10 hrs/day, has been shown to improve blood pressure in various cardiometabolic diseases, yet there is limited data on the effect in SS hypertension. The goal of this study was to examine the effect of TRF on disease development in the Dahl SS rat. We hypothesized that implementing TRF during a critical timepoint in disease progression would reduce mean arterial blood pressure (MAP). To study this, femoral catheters were surgically implanted in male Dahl SS rats at 9±0.5 weeks of age (n=5-7/group), allowing for urine and arterial blood sample collection from conscious rats during continual blood pressure recording. After 1 week of recovery, rats either continued a low salt (LS;0.4% NaCl) diet or were switched to a high salt diet (HS;4% NaCl) with ad libitum (ad lib) access for 1 week. At the start of week 2, a subset of rats began TRF, in which food was provided for 8 hrs (10PM-6AM) during their active period for an additional week. Rats meeting the following criteria were included in analysis: pulse pressure > 10 mmHg, baseline MAP of 115-130 mmHg, and a 10-20 mmHg increase in MAP after 1 week on HS. Differences in MAP were analyzed by 2-way ANOVA with Tukey multiple comparisons and data are reported as mean ± SEM. By the end of week 2, HS TRF rats trended toward lower average MAP compared to HS ad lib rats (141.51±3.41 vs 149.49±1.65 mmHg; p=0.07). However, we found that the HS TRF rats had reduced MAP during their active period (6PM-6AM), compared to the HS ad lib rats (142.60±2.99 vs 151.65±1.862 mmHg; p<0.05), but no difference during the inactive period (6AM-6PM). At the end of the study, average MAP was calculated every 4 hrs to identify the timing at which TRF reduced MAP. We found that the HS TRF rats had lower MAP from 6PM to 10PM (134.61±2.34 vs 146.75±1.21 mmHg; p<0.05) and 10PM to 2AM (144.58±2.79 vs 154.70±2.18 mmHg; p<0.05) when compared to the HS ad lib rats. The LS TRF group also had lower pressure from 6PM-10PM compared to the LS ad lib group (124.93±1.19 vs 130.56±0.73 mmHg; p<0.05), suggesting that this time-specific reduction in MAP may be due to fasting, as there were no other differences in MAP within the LS groups. This suggests that TRF may slow progression of hypertension development in the Dahl SS rat, primarily by affecting MAP during the active period. Future studies will examine how TRF affects Na + handling to further understand these time-dependent effects.

Time-Restricted Feeding Protects against Renal Ischemia-Reperfusion Injury in Mice.

Ischemia-reperfusion injury (IRI) in the kidneys is a major cause of acute kidney injury (AKI). Time-restricted feeding (TRF), known for its metabolic health benefits and alleviation of various chronic diseases without calorie restriction, was investigated for its potential protective effects against IRI-induced AKI. Male C57BL/6 mice underwent unilateral IRI, with their kidneys collected after two days. For two weeks before IRI induction, the TRF group had unlimited access to standard chow but within an 8-hour feeding window during the dark cycle. The study groups were Control, TRF, IRI, and TRF + IRI. In the TRF + IRI group, tubular damage scores significantly decreased compared to the IRI group. Furthermore, the TRF + IRI mice had lower levels of phosphorylated NF-κB and fewer F4/80-positive macrophages than the IRI group. Oxidative stress markers for lipids and proteins were also notably lower in the TRF + IRI group. Additionally, TUNEL-positive tubular cells and cleaved caspase-3 expression were reduced in the TRF + IRI group. Without calorie restriction, TRF mitigated renal damage by reducing inflammation, oxidative stress, and tubular apoptosis in renal IRI. This suggests that TRF could be a promising dietary strategy to prevent IRI-induced AKI.

Time-Restricted Feeding (16/8)

This study aimed to investigate the effects of 8-hour time-restricted feeding (TRF) on body weight, biochemical parameters, diet quality, and eating behavior in overweight females. In the TRF group, there was a statistically significant decrease in body weight, body mass index, and waist and hip circumference (P < .05). Furthermore, there was a statistically significant greater decrease in blood glucose, insulin, cholesterol, and low-density lipoprotein cholesterol in the TRF group (P < .05). TRF did not affect eating behavior or diet quality (P > .05), but it led to a decrease in fiber intake (P < .05). These findings suggest that consuming food within an 8-hour window may facilitate weight loss in individuals with obesity. Longitudinal studies with larger samples are needed to confirm this.

Effect of Fasting During Time Restricted Feeding on Mitochondrial Beta-Oxidation Enzyme Expression in the Kidney Cortex of Adult Male Salt-Sensitive Dahl Rats

The Dahl salt-sensitive (SS) rat is a well-characterized model of SS hypertension and renal disease that exhibits enhanced Na+ reabsorption in the kidney. Prior research has shown that SS rats experience a reduction in fatty acid beta oxidation (FAO) in the kidney cortex when placed on a high salt (HS) diet. Time restricted feeding (TRF), a type of intermittent fasting in which food consumption is restricted to <10 hrs/day, has been shown to activate FAO. Since the proximal tubule is responsible for the highest amount of Na+ reabsorption, we are interested in understanding if intermittent salt intake via TRF can mitigate dysfunctional cortical metabolism and slow progression of renal damage. We hypothesized that fasting during TRF would activate FAO throughout the body, as well as in the kidney cortex. To study this, 10-week-old male SS rats were provided ad libitum access to 4.0% NaCl (high salt; HS) or 0.4% (low salt; LS) diet for one week. Rats were then placed into a Promethion Core system (Sable Systems International) for metabolic phenotyping, where some continued ad libitum feeding, and others began time restricted feeding (TRF) for an additional week (n=7-9/group). During TRF, food was provided for 8 hours during the active cycle (2200hrs-0600hrs). Rats were euthanized in the last two hours of the final fasting period. We found that during the last hour of the fasting period, when compared to ad libitum rats, both the LS TRF (0.824 ± 0.01 vs 0.986 ± 0.008) and HS TRF (0.830 ± 0.01 vs 0.980 ± 0.006) rats had a significant reduction in their respiratory exchange ratio (2-way ANOVA with Tukey multiple comparisons, p<0.05, mean ± SEM). This suggests that the TRF protocol induced a net whole-body shift in fuel utilization from primarily carbohydrates to a mix of fuel sources by the end of the 16-hour fasting period, regardless of diet. To investigate the effect of fasting during TRF on the kidney cortex, we performed western blot analysis of acyl-CoA dehydrogenase long chain (ACADL) and acetyl-CoA acyltransferase 2 (ACAA2), enzymes involved in initial and final steps of mitochondrial beta-oxidation, respectively. We found that HS rats had lower ACADL and ACAA2 expression than the LS rats (2-way ANOVA; main effect of HS, p<0.05), and there was no difference between ad libitum and TRF groups within LS or HS groups (2-way ANOVA; main effect of TRF, p>0.05). This data suggests that, even though whole-body FAO may be stimulated by TRF fasting, HS-induced suppression of mitochondrial FAO proteins ACADL and ACAA2 was not restored by TRF. Future studies will investigate the effects of the shift in fuel utilization on other metabolic pathways in the cortex and proximal tubules. Supported by the Advancing a Healthier Wisconsin Endowment, the Medical College of Wisconsin, and NIH 5T32HL007852-25. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Time-restricted feeding does not improve nephropathy in humanized sickle cell disease mice

Sickle cell disease (SCD) is an autosomal recessive genetic disease caused by a point mutation in the hemoglobin gene. This substitution results in a “sickling” of red blood cells and subsequent vascular and organ damage. Current treatments, while increasing the lifespan of sickle cell patients, has resulted in a higher prevalence of chronic complications like SCD nephropathy. Our group has previously shown that time-restricted feeding (TRF) in chronic high fat fed mice reduces kidney damage. Given the increased kidney damage in SCD, we hypothesize that TRF in humanized SCD mice will attenuate sickle cell nephropathy. To test this hypothesis, we studied 18-22-week-old male SCD mice. Mice underwent 3 weeks of TRF, only having access to food during the active, dark period (Zeitgeber Time (ZT) 12 to 24). The control group had access to food ad libitum (ad-lib). At the end of the 3 weeks, at 21-25 week old ages, 12 hour urine was collected in metabolic cages as well as kidneys and plasma collection at ZT3 (inactive period). Excretion of urinary kidney damage markers (albumin and NGAL-1) showed no difference between TRF and ad-lib in both the active and inactive collection periods. Urinary excretion of endothelin-1 is known to be upregulated in SCD patients; however, TRF did not change this marker in SCD mice. TRF did not change plasma levels of cytokines or soluble adhesion molecules. Histological analysis of kidneys was conducted as an additional marker of kidney damage. We analyzed iron levels in the kidney with Prussian blue staining as well as fibrosis with Masson’s trichrome. TRF did not change kidney iron accumulation or kidney fibrosis. Immunohistochemical staining for CD3+ T cells did not show a difference in glomerular T cell infiltration in the TRF group compared to the ad-lib group. In conclusion, TRF does not appear to have an effect on renal inflammation or kidney function in SCD mice, but future studies need to be completed. R01 DK134562. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Transient anticonvulsant effects of time-restricted feeding in the 6-Hz mouse model

IntroductionIntermittent fasting enhances neural bioenergetics, is neuroprotective, and elicits antioxidant effects in various animal models. There are conflicting findings on seizure protection, where intermittent fasting regimens often cause severe weight loss resembling starvation which is unsustainable long-term. Therefore, we tested whether a less intensive intermittent fasting regimen such as time-restricted feeding (TRF) may confer seizure protection. MethodsMale CD1 mice were assigned to either ad libitum-fed control, continuous 8 h TRF, or 8 h TRF with weekend ad libitum food access (2:5 TRF) for one month. Body weight, food intake, and blood glucose levels were measured. Seizure thresholds were determined at various time points using 6-Hz and maximal electroshock seizure threshold (MEST) tests. Protein levels and mRNA expression of genes, enzyme activity related to glucose metabolism, as well as mitochondrial dynamics were assessed in the cortex and hippocampus. Markers of antioxidant defence were evaluated in the plasma, cortex, and liver. ResultsBody weight gain was similar in the ad libitum-fed and TRF mouse groups. In both TRF regimens, blood glucose levels did not change between the fed and fasted state and were higher during fasting than in the ad libitum-fed groups. Mice in the TRF group had increased seizure thresholds in the 6-Hz test on day 15 and on day 19 in a second cohort of 2:5 TRF mice, but similar seizure thresholds at other time points compared to ad libitum-fed mice. Continuous TRF did not alter MEST seizure thresholds on day 28. Mice in the TRF group showed increased maximal activity of pyruvate dehydrogenase in the cortex, which was accompanied by increased protein levels of mitochondrial pyruvate carrier 1 in the cortex and hippocampus. There were no other major changes in protein or mRNA levels associated with energy metabolism and mitochondrial dynamics in the brain, nor markers of antioxidant defence in the brain, liver, or plasma. ConclusionsBoth continuous and 2:5 TRF regimens transiently increased seizure thresholds in the 6-Hz model at around 2 weeks, which coincided with stability of blood glucose levels during the fed and fasted periods. Our findings suggest that the lack of prolonged anticonvulsant effects in the acute electrical seizure models employed may be attributed to only modest metabolic and antioxidant adaptations found in the brain and liver. Our findings underscore the potential therapeutic value of TRF in managing seizure-related conditions.

Abstract P400: Effects Of Time Restricted Feeding On Blood Pressure And Urine Output

Americans consume ~48% more salt than the recommended daily intake, increasing the sodium load placed on the kidneys. Normally, the kidneys excrete this excess sodium, however salt-sensitive (SS) individuals are unable to do so and develop hypertension. Time-restricted feeding (TRF), in which food is consumed in <10 hours, has been shown to improve various cardiometabolic disorders, however there is limited research on its effect in SS hypertension. The goal of this study was to determine if intermittent salt consumption via TRF can improve SS hypertension in the Dahl SS rat model. Male (n=7-9/group) and female (n=4/group) SS rats were randomly divided into the following groups: low salt ad libitum (LS ad lib), low salt TRF (LS TRF), high salt ad libitum (HS ad lib), or high salt TRF (HS TRF) and underwent a two-week protocol. During the first week, all rats had ad libitum access to their respective diet to establish hypertension in the HS groups. During the second week, some animals began TRF, in which food was provided for 8 hours during the active period (2200-0600 hrs), and metabolic phenotypes were assessed in all rats using the Promethion (Sable Systems). Urine was collected for 8-9 hrs after the feeding period. Prior to endpoint, anesthetized blood pressure was measured at the end of the fasting period. We found that the HS TRF group had reduced systolic blood pressure in both males (138.69 ± 4.29 mmHg vs 143.33 ± 7.43 mmHg; mean ± SEM) and females (129.19 ± 6.29 mmHg vs 135.85 ± 10.88 mmHg; mean ± SEM) compared to the HS ad lib group, however this was not significant. Urine excretion was significantly higher in the HS TRF group compared to the HS ad lib group in both males (8.89 ± 1.06 mL vs 4.06 ± 0.42 mL; mean ± SEM; p<0.05) and females (7.5 ± 0.20 mL vs 4.88 ± 0.43 mL; mean ± SEM; p<0.05). Furthermore, while the rats were in the Promethion, there was a higher amount of water loss (VH 2 O; which can include evaporated urine) in the HS TRF group compared to the HS ad lib group during the fasting period in both males (1.52 ± 0.03 g/hr vs 1.40 ± 0.03 g/hr; mean ± SEM; p<0.05) and females (1.18 ± 0.03 g/hr vs 0.96 ± 0.01 g/hr; mean ± SEM; p<0.05). Overall, these results may suggest that TRF produces a diuretic effect in the Dahl SS rat model, however further studies are required to confirm this.

Impact of Feeding Time and Duration on Body Mass and Composition in Young, Exercising Mice

Time-restricted feeding (TRF) has increased in popularity among various groups, including fitness enthusiasts. The ideal timing of TRF in relation to daily exercise is unknown. Most fitness enthusiasts consume meals immediately or soon after exercise to improve body composition (e.g., lean mass). We compared two different TRF approaches, as well as an <em>ad libitum</em> control diet, with regards to body mass and body composition in C57BL/6 mice<strong>. </strong>Young, healthy, male mice exercised five days per week and were assigned to consume food <em>ad libitum</em> (control), or to follow a 6-hour TRF that began immediately after exercise (TRF-I) or 5 hours after exercise (TRF-D); n = 12 mice per group. Body mass, lean mass, and fat mass were assessed weekly. Due to animal deaths, only 10 animals were included in the analysis for each TRF group, with 8 animals included for the control group. When computing the 8-week average, body mass varied between groups (p < 0.0001), with the TRF-I (25.4 ± 1.7 g) weighing less than the TRF-D (26.3 ± 2.3 g) and control (26.9 ± 2.3 g). Lean mass also differed (p < 0.0001), with control (22.8 ± 1.9 g) higher than TRF-I (21.4 ± 1.7 g) and TRF-D (21.7 ± 1.8 g). Additionally, fat mass differed between groups (p < 0.0001), with the TRF-D (2.7 ± 0.9 g) higher than the TRF-I (2.2 ± 0.9 g) and control (2.0 ± 1.2 g). Finally, percent body fat differed (p < 0.0001), with TRF-D (10.5 ± 3.3%) higher than TRF-I (8.6 ± 3.7%) and control (7.5 ± 4.3%). At the end of the 8-week intervention, TRF-I was lower in fat mass and percent body fat than TRF-D (p < 0.05), while body mass and lean mass were higher for control as compared to both TRF groups (p < 0.05). These results indicate that when combined with regular exercise, <em>ad libitum</em> feeding may be more beneficial (greater overall and lean mass gain) than TRF, regardless of feeding timing.

Effects of alternate-day fasting and time-restricted feeding in obese middle-aged female rats

ObjectivesObesity is a multifactorial condition associated with metabolic alterations that can be aggravated during female aging. Calorie restriction via intermittent fasting (IF) diets may reduce body weight and therefore have the potential to decrease obesity and associated comorbidities, such as insulin resistance. This study investigated the effects of two IF protocols, alternate-day fasting (ADF) and time-restricted feeding (TRF) in middle-aged obese female rats. MethodsWistar rats (age 15 mo) were fed with standard chow or high-fat diet for 8 wk and then separated into the following groups (n = 5–8 each) for another 8 wk: control (received standard chow), obese (received high-fat diet), obese + ADF (24-h fasting protocol), and obese + TRF (14 h daily). ResultsAt the end of the study, both IF protocols were able to reduce body weight and body mass index compared with the obese group. However, no changes were observed in adiposity and glucose homeostasis. We also found an increase in total leukocytes, lymphocytes, and monocytes in the TRF group and a higher number of platelets in the ADF group. Blood lipid profiles, including triglycerides and high-density lipoprotein, as well as liver stress responses, such as heat shock protein 70 and malondialdehyde, were not changed by IF. ConclusionsAlthough ADF and TRF protocols resulted in a reduction of body weight and body mass index, these dietary interventions did not promote health benefits, such as reducing blood lipid profile, adiposity, and insulin resistance. In addition, ADF and TRF increased inflammatory biomarkers, which may increase the risk of obesity-associated comorbidities.

Effect of time restricted feeding on anthropometric measures, eating behavior, stress, serum levels of BDNF and LBP in overweight/obese women with food addiction: a randomized clinical trial

ABSTRACT Background & aim Food addiction (FA) as a specific food-related behavior may play an essential role in the pathogenesis of obesity. Brain-derived neurotrophic factor (BDNF) and gut microbiota (GM) alterations probably through fasting are closely related to brain function, affecting eating behaviors and body weight management. This study aimed to evaluate the effect of time-restricted feeding (TRF) on serum BDNF levels and eating behaviors in overweight and obese women with FA. Methods and design This clinical trial was performed with a 2-month follow-up on 56 obese and overweight women with FA. Participants were randomly divided into two groups receiving a low-calorie diet (n = 27) and a group receiving a low-calorie diet with TRF (n = 29). Anthropometric measurements, biochemical markers, eating behavior, and stress were assessed during the study period. Results The reductions in weight, body mass index (BMI), waist circumference, and body fat mass were significantly higher in the TRF group compared to the control group at week 8 (P = 0.018, P = 0.015. P = 0.03, and P = 0.036, respectively). The cognitive restriction score was higher in the TRF as compared with the control group (P = 0.002). The food addiction criteria score was significantly reduced in both groups (P < 0.001). Serum levels of BDNF were significantly increased in the TRF group (P < 0.001). In addition, BDNF levels had a positive and significant correlation with the cognitive restriction score (r = 0.468 and P < 0.001), While the correlation with FA was not significant (β = 0.588 and P = 0.618). Lipopolysaccharide binding protein decreased significantly in both groups, but this decrease was significantly higher in the TRF group than in the control group (P < 0.001). Conclusion The results of this study showed that a low-calorie diet with TRF is more effective in weight management than a low-calorie diet alone, probably through further modulating the GM and improving BDNF levels. More effective weight loss in the TRF is probably related to better management of eating behavior than FA. Trial registration Iranian Registry of Clinical Trials identifier: IRCT20131228015968N7.

Post-Effects of Time-Restricted Feeding against Adipose Tissue Inflammation and Insulin Resistance in Obese Mice.

Time-restricted feeding (TRF) has been shown to improve the disordered metabolic and immunologic functions associated with obesity, however little is known about its post-effects after the cessation of TRF practice. In the current study, we determined how long the effects of TRF persist, and whether the effects are tissue-dependent. There were four groups of mice in this study: overweight and obese mice were randomized into (1) TRF group (TRF for 6 weeks), (2) post-TRF group (TRF for 4 weeks and later ad libitum), (3) continuous ad libitum of high-fat diet (HFD-AL), and (4) the lean control-fed low-fat diet ad libitum. Blood, liver, and adipose tissues were collected to measure the metabolic, inflammatory, and immune cell parameters. The results showed that TRF withdrawal quickly led to increased body weight/adiposity and reversed fasting blood glucose. However, fasting insulin and insulin resistance index HOMA-IR remained lower in the post-TRF than in the HFD-AL group. In addition, TRF-induced reduction in blood monocytes waned in the post-TRF group, but the TRF effects on mRNA levels of proinflammatory immune cells (macrophages Adgre1 and Itgax) and cytokine (Tnf) in adipose tissue remained lower in the post-TRF group than in the HFD-AL group. Furthermore, the TRF group was protected from the down-regulation of Pparg mRNA expression in adipose tissue, which was also observed in the post-TRF group to a lesser extent. The post-TRF animals displayed liver mass similar to those in the TRF group, but the TRF effects on the mRNA of inflammation markers in the liver vanished completely. Together, these results indicate that, although the lasting effects of TRF may differ by tissues and genes, the impact of TRF on adipose tissue inflammation and immune cell infiltration could last a couple of weeks, which may, in part, contribute to the maintenance of insulin sensitivity even after the cessation of TRF.

Time-restricted feeding affects colonic nutrient substrates and modulates the diurnal fluctuation of microbiota in pigs.

Studies demonstrate that time-restricted feeding (TRF) can regulate gut microbiota composition. However, it is unclear whether TRF could affect the gut microbial rhythmicity in growing pigs. Therefore, the present study aimed to explore the effects of TRF on the dynamic fluctuation of the gut microbiota. A total of 10 healthy growing pigs equipped with T cannula were employed. Pigs were randomly allotted to the free access (FA) and the TRF groups with 5 replicates (1 pig/replicates). Pigs in the FA group were fed free access during the whole experimental period, whereas pigs in the TRF group were fed free access three times per day within limited times (7:00-8:00, 12:00-13:00, 17:00-18:00). The experiment lasted for 15 days, at 06:00 a.m. of the day 16, colonic digesta were collected at a 6-h interval for consecutive 24 h marked as T06 (06:00), T12 (12:00), T18 (18:00), T24 (24:00), T30 (06:00), respectively. Results showed that TRF altered the distribution of feed intake without changing the total feed intake within a day (p = 0.870). TRF decreased the overall concentration of colonic cellulose and altered their oscillating patterns. All alpha-diversity indexes of different time points showed significant differences regardless of feeding pattern with a trough at T18 or T24. TRF shifted the trough of the alpha-diversity index Simpson and Invsimpson. TRF lost the rhythmicity of Prevotellaceae, Ruminococcaceae, Bacteroidales_S24-7_group, and Peptococcaceae and gained the rhythmicity of Pasteurellaceae, Clostridiaceae_1, Veillonellaceae, and Peptostreptococcaceae. Also, TRF altered the interaction pattern by increasing the microbes involved in the co-occurrence network and their crosstalk, especially at T24. Interestingly, the microbial variation at T24 could largely explained by colonic substrates starch (R2 = 0.369; p = 0.001), cellulose (R2 = 0.235; p = 0.009) and NH4-N (R2 = 0.489; p = 0.001). In conclusion, TRF has changed the concentrates of cellulose and the relative abundance of specific microbes and certain microbial metabolites. In addition, TRF has more powerful effects on the fluctuation modes of these nutrient substrates, microbes, and metabolites by shifting their peaks or troughs. This knowledge facilitates the development of precision regulation targeting gut microbial rhythmicity.

Time-Restricted Feeding Ameliorates Uterine Epithelial Estrogen Receptor α Transcriptional Activity at the Time of Embryo Implantation in Mice Fed a High-Fat Diet

BackgroundMore than 30% of reproductive-age women are obese or overweight. Obesity and exposure to a high-fat diet (HFD) detrimentally affect endometrial development and embryo implantation. We previously reported that time-restricted feeding (TRF) improved ovarian follicular development, but whether and how TRF modulates embryo implantation are poorly understood. ObjectiveWe investigated the effect of TRF on embryo implantation. MethodsIn TRF group, mice had 10 h of food free access from 9 pm to 7 am, and fed a normal diet or a HFD. Tail vein injection of Chicago blue dye was used to examine embryo implantation sites at day 5.5 (D5.5) of pregnancy. Serum collected at D0.5 and D4.5 of pregnancy was used to examine the level of estradiol (E2) and progesterone. Uterine estrogen receptor (ER) and progesterone receptor levels and their targeted aquaporins (AQPs) were measured. LC–MS was used to analyze bile acid (BA) composition, and primary hepatocytes were used to test the effects of BA on the expression level of SULT1E1, a key enzyme in estrogen inactivation and elimination. ResultsWe found that TRF prevented HFD-induced embryo loss and alleviated the defect in luminal closure on D4.5 of pregnancy. The cyclic changes of E2 level were lost in mice fed ad libitum but not in TRF mice on the HFD. The HFD increased ER-α expression and transcriptional activity, which induced AQP3 and AQP5 expression on D4.5 of pregnancy. TRF prevented the negative effect of the HFD on uterine luminal closure. Furthermore, in vitro and in vivo results showed that BA suppressed estrogen degradation by activating liver SULT1E1 expression. ConclusionsOur findings demonstrated that TRF prevented HFD-induced defects in luminal closure, thereby improving embryonic implantation, and provide novel insights into the effects of dietary intervention on obesity and associated infertility.

PS-B07-11: EFFECT OF TRF INTERVENTION ON DIET INDUCED OBESITY: A NON-PHARMACOLOGICAL THERAPEUTIC STRATEGY

Objectives: Time-restricted feeding (TRF) regulates the circadian rhythm of food intake that protects against metabolic disorders. The aim of our study are 12 hours time restricted feeding effects on diet induces obesity in rats model. Material &amp; Method: Total 21 Wistar rats were included i.e. control, TRF and High Fat diet (HFD) group. HFD group was fed with fatty diet at ad lib for two months and shifted to TRF (12 hours feeding i.e 8:00pm - 8:00am) for three months, after which they were again put back on ad lib. TRF group fed chow diet during 8:00pm to 8:00am for three months and then these rats shifted to ad lib for three months. Control group fed chow diet at ad lib. Body weight was calculated and blood samples were collected to measure blood glucose, insulin, lipid profile and gene expression. Results: The body weight of HFD group were significantly increased and TRF with chow diet were significantly decreased as compared to control rats (p = 0.0263) and (p = 0.0054) respectively. The level of HDL was reduced in rats fed with HFD whereas total cholesterol, TG and LDL were increased. TRF intervention with HFD diet reduced body weight, blood glucose level, TG and LDL and elevated the level of insulin, total cholesterol and HDL. Per1 and Bmal1 gene were up regulated in HFD group and after TRF intervention had reduced mRNA expression. TRF intervention with HFD and chow diet showed its legacy effect when put on ad lib. Conclusion: TRF intervention is easily adaptable lifestyle modification and non-pharmacological strategy can reduces the risk factor of obesity and its associated metabolic disorders.

Efficacy and mechanism of intermittent fasting in metabolic associated fatty liver disease based on ultraperformance liquid chromatography-tandem mass spectrometry.

Drug treatment of metabolic associated fatty liver disease (MAFLD) remains lacking. This study analyzes the efficacy and mechanism underlying intermittent fasting combined with lipidomics. Thirty-two male rats were randomly divided into three groups: Normal group, administered a standard diet; MAFLD group, administered a 60% high-fat diet; time-restricted feeding (TRF) group, administered a 60% high-fat diet. Eating was allowed for 6 h per day (16:00-22:00). After 15 weeks, liver lipidomics and other indicators were compared. A total of 1,062 metabolites were detected. Compared with the Normal group, the weight, body fat ratio, aspartate aminotransferase, total cholesterol, low-density cholesterol, fasting blood glucose, uric acid, and levels of 317 lipids including triglycerides (TG) (17:0-18:1-20:4) were upregulated, whereas the levels of 265 lipids including phosphatidyl ethanolamine (PE) (17:0-20:5) were downregulated in the MAFLD group (P < 0.05). Compared with the MAFLD group, the weight, body fat ratio, daily food intake, and levels of 253 lipids including TG (17:0-18:1-22:5) were lower in the TRF group. Furthermore, the levels of 82 lipids including phosphatidylcholine (PC) (20:4-22:6) were upregulated in the TRF group (P < 0.05), while serum TG level was increased; however, the increase was not significant (P > 0.05). Enrichment analysis of differential metabolites showed that the pathways associated with the observed changes mainly included metabolic pathways, regulation of lipolysis in adipocytes, and fat digestion and absorption, while reverse-transcription polymerase chain reaction showed that TRF improved the abnormal expression of FAS and PPARα genes in the MAFLD group (P < 0.05). Our results suggest that 6 h of TRF can improve MAFLD via reducing food intake by 13% and improving the expression of genes in the PPARα/FAS pathway, thereby providing insights into the prevention and treatment of MAFLD.

Time-restricted feeding affects transcriptomic profiling of hypothalamus in pigs through regulating aromatic amino acids metabolism.

Time-restricted feeding (TRF) is an effective means that can efficiently regulate the metabolism and health of animals and humans. However, the effect of TRF on hypothalamic function remains unclear. Results showed that TRF significantly increased the activities of digestive enzymes lipase, maltase in the duodenum and lipase, trypsin in the pancreas whereas significantly decreased serum gastrointestinal hormones gastrin, glucagon-like peptide-1, cholecystokinin, peptide YY, and ghrelin. Metabolites related to amino acid metabolism, including citrulline, kynurenine, N-acetylleucine, l-tryptophan, and l-tyrosine, significantly increased in the TRF group. Differential metabolites were mainly enriched in phenylalanine, tyrosine, and tryptophan biosynthesis and tryptophan metabolism. Transcriptomic analysis of hypothalamus showed that a total of 462 differentially expressed genes (DEGs) were significantly changed by TRF. In particular, DEGs such as DDC, TH, GOT2, and DBH involved in aromatic amino acid metabolism pathways were significantly downregulated, whereas the expression of CYP1B1 was significantly upregulated. Moreover, DEGs (PDYN and PPP3CA) involved in amphetamine addiction and cocaine addiction were also downregulated in the TRF group. Taken together, these results suggested that TRF improved the digestion and absorption of nutrients and thus increased the accessibilities of aromatic amino acids. The increasing of circulating aromatic amino acids might mediate the regulatory neuroendocrine effects of TRF regimes on the hypothalamus functions, especially on drug addictions. This study reveals a possible mechanism underlying the effects of regulating feeding patterns on the function of the hypothalamus by altering aromatic amino acids metabolism. © 2022 Society of Chemical Industry.

Alternate day fasting and time-restricted feeding may confer similar neuroprotective effects during aging in male rats.

Age associated neurodegenerative changes are acknowledged to play a causative role in a majority of neurological diseases that accompany aging in organisms. To alleviate the deteriorative effects of aging in the brain, we investigated the effects oftwo types of intermittent fasting (IF) methods: alternate day fasting (ADF) and time- restricted feeding (TRF) in young (3months) and old (24months) in male Wistar rats comparing the results with age matched controls. The evaluation of biomarkers of oxidative stress showed significant decline in the old (ADF and TRF) groups in addition to up regulation in antioxidant levels. It was observed that ADF and TRF methods helped reduce ROS accumulation in the mitochondria and increased the activity of the electron transport chain complexes especially C-I and III. Gene expression analysis of autophagy genes like beclin and LC3B showed upregulated expression in ADF and TRF group. Sirtuin1 expression too significantly increased during fasting in both young and old groups showing fasting induced protection from aging. Histological analysis of sections of cerebral cortex and CA1 area provide evidence that fasting protected neurons against degeneration with age. Our results prompt us to conclude that the efficacy of these fasting methods ADF and TRF are reliable anti- aging strategies with respect to dietary restriction interventions. Moreover, both these methods compete closely in conferring protection from oxidative stress and inducing neuroprotective changes in brain of aged rats when compared to their young counterparts.

Beneficial effects of time-restricted feeding on gentamicin cytotoxicity in mouse cochlea and vestibular organs.

ObjectiveTime restricted feeding (TRF), which is an intermittent fasting protocol, has been reported to decrease the toxicity and mortality rate associated with systemic gentamicin (GM) administration. The aim of this study is to evaluate the effect of TRF on GM‐induced vestibular and auditory function in mice.MethodsJapan Central Laboratory for Experimental Animals:Institute of Cancer Research (Jcl:ICR) mice were housed in a light–dark (LD) cycle (12:12) and were divided into three groups: (1) GM treatment at a dose of 220 mg/kg with TRF (feeding time: 8 h [9:00–17:00] during the light phase [7:00–19:00]) (GM + TRF group), (2) GM treatment at a dose of 220 mg/kg without TRF (GM group), and (3) saline injection with TRF (NS + TRF group). GM or saline was injected subcutaneously for 18 days (three courses of 5 days' injection + 2 days' rest, and an additional 3 days' injection). The auditory brainstem response (ABR) and vestibular evoked potential (VsEP) were tested after the treatments. The number of sensory hair cells in the cochlear organs and the vestibular organs were quantified using microscopic images.ResultsAll animals survived until the end of the experiment. One day after the last injection, GM + TRF mice showed significantly lower ABR thresholds at 4 kHz compared to GM mice, and there was no significant difference between the GM + TRF and NS + TRF groups. There was a significant difference of VsEP between GM and GM + TRF mice only in symmetric parabolic waves with linear acceleration and ramps waveform stimulation. GM + TRF mice showed significantly less outer and inner hair cell loss compared to GM mice. GM + TRF mice showed significantly less type II hair cell loss in the utricle and the ampulla compared to GM mice.ConclusionTRF with daytime feeding reduced GM cytotoxicity in the cochlea and vestibular organs of ICR mice.Level of EvidenceNA