Effects of a ketogenic diet during pregnancy on embryonic growth in the mouse

Element Changes Occurring in Brain Point at the White Matter Abnormalities in Rats Exposed to the Ketogenic Diet During Prenatal Life

A large number of clinical studies demonstrate that the ketogenic diet (KD) may be an effective approach to the reduction of epileptic seizures in children and adults. Such dietary therapy could also help pregnant women with epilepsy, especially since most antiseizure drugs have teratogenic action. However, there is a lack of medical data, considering the safety of using KD during gestation for the progeny. Therefore, we examined the influence of KD used prenatally in rats on the elemental composition of the selected brain regions in their offspring. For this purpose, synchrotron radiation-induced X-ray fluorescence (SR-XRF) microscopy was utilized, and elements such as P, S, K, Ca, Fe, and Zn were determined. Moreover, to verify whether the possible effects of KD are temporary or long-term, different stages of animal postnatal development were taken into account in our experiment. The obtained results confirmed the great applicability of SR-XRF microscopy to track the element changes occurring in the brain during postnatal development as well as those induced by prenatal exposure to the high-fat diet. The topographic analysis of the brains taken from offspring of mothers fed with KD during pregnancy and appropriate control individuals showed a potential influence of such dietary treatment on the brain levels of elements such as P and S. In the oldest progeny, a significant reduction of the surface of brain areas characterized by an increased P and S content, which histologically/morphologically correspond to white matter structures, was noticed. In turn, quantitative elemental analysis showed significantly decreased levels of Fe in the striatum and white matter of 30-day-old rats exposed prenatally to KD. This effect was temporary and was not noticed in adult animals. The observed abnormalities may be related to the changes in the accumulation of sphingomyelin and sulfatides and may testify about disturbances in the structure and integrity of the myelin, present in the white matter.

Imaging brain glucose metabolism in vivo reveals propionate as a major anaplerotic substrate in pyruvate dehydrogenase deficiency

A vexing problem in mitochondrial medicine is our limited capacity to evaluate the extent of brain disease in vivo. This limitation has hindered our understanding of the mechanisms that underlie the imaging phenotype in the brain of patients with mitochondrial diseases and our capacity to identify new biomarkers and therapeutic targets. Using comprehensive imaging, we analyzed the metabolic network that drives the brain structural and metabolic features of a mouse model of pyruvate dehydrogenase deficiency (PDHD). As the disease progressed in this animal, in vivo brain glucose uptake and glycolysis increased. Propionate served as a major anaplerotic substrate, predominantly metabolized by glial cells. A combination of propionate and a ketogenic diet extended lifespan, improved neuropathology, and ameliorated motor deficits in these animals. Together, intermediary metabolism is quite distinct in the PDHD brain-it plays a key role in the imaging phenotype, and it may uncover new treatments for this condition.

Ketone Bodies in Diabetes Mellitus: Friend or Foe?

In glucose-deprived conditions, ketone bodies are produced by the liver mitochondria, through the catabolism of fatty acids, and are used peripherally, as an alternative energy source. Ketones are produced in the body under normal conditions, including during pregnancy and the neonatal period, when following a ketogenic diet (KD), fasting, or exercising. Additionally, ketone synthesis is also augmented under pathological conditions, including cases of diabetic ketoacidosis (DKA), alcoholism, and several metabolic disorders. Nonetheless, diet is the main regulator of total body ketone concentrations. The KDs are mimicking the fasting state, altering the default metabolism towards the use of ketones as the primary fuel source. Recently, KD has gained recognition as a medical nutrition therapy for a plethora of metabolic conditions, including obesity and diabetes mellitus (DM). The present review aims to discuss the role of ketones, KDs, ketonemia, and ketonuria in DM, presenting all the available new evidence in a comprehensive manner.

Molecular pathways and nutrigenomic review of insulin resistance development in gestational diabetes mellitus

Gestational diabetes mellitus is a condition marked by raised blood sugar levels and insulin resistance that usually occurs during the second or third trimester of pregnancy. According to the World Health Organization, hyperglycemia affects 16.9% of pregnancies worldwide. Dietary changes are the primarily alternative treatment for gestational diabetes mellitus. This paper aims to perform an exhaustive overview of the interaction between diet, gene expression, and the metabolic pathways related to insulin resistance. The intake of foods rich in carbohydrates can influence the gene expression of glycolysis, as well as foods rich in fat, can disrupt the beta-oxidation and ketogenesis pathways. Furthermore, vitamins and minerals are related to inflammatory processes regulated by the TLR4/NF-κB and one carbon metabolic pathways. We indicate that diet regulated gene expression of PPARα, NOS, CREB3L3, IRS, and CPT I, altering cellular physiological mechanisms and thus increasing or decreasing the risk of gestational diabetes. The alteration of gene expression can cause inflammation, inhibition of fatty acid transport, or on the contrary help in the modulation of ketogenesis, improve insulin sensitivity, attenuate the effects of glucotoxicity, and others. Therefore, it is critical to comprehend the metabolic changes of pregnant women with gestational diabetes mellitus, to determine nutrients that help in the prevention and treatment of insulin resistance and its long-term consequences.

Does Ketogenic Diet Used in Pregnancy Affect the Nervous System Development in Offspring?─FTIR Microspectroscopy Study

Anti-seizure medications used during pregnancy may have transient or long-lasting impact on the nervous system of the offspring. Therefore, there is a great need to search for alternative therapies for pregnant women suffering from seizures. One of the solutions may be the use of the ketogenic diet (KD), which has been successfully applied as a treatment of drug-resistant epilepsy in children and adults. However, the risks associated with the use of this dietary therapy during pregnancy are unknown and more investigation in this area is needed. To shed some light on this problem, we attempted to determine the potential abnormalities in brain biomolecular composition that may occur in the offspring after the prenatal exposure to KD. To achieve this, the female Wistar rats were, during pregnancy, fed with either ketogenic or standard laboratory diet, and for further studies, their male offspring at 2, 6, or 14 days of age were used. Fourier transform infrared microspectroscopy was applied for topographic and quantitative analysis of main biological macromolecules (proteins, lipids, compounds containing phosphate and carbonyl groups, and cholesterol) in brain samples. Performed chemical mapping and further semi-quantitative and statistical analysis showed that the use of the KD during pregnancy, in general, does not lead to the brain biochemical anomalies in 2 and 6 days old rats. The exception from this rule was increased relative (comparing to proteins) content of compounds containing phosphate groups in white matter and cortex of 2 days old rats exposed prenatally to KD. Greater number of abnormalities was found in brains of the 14 days old offspring of KD-fed mothers. They included the increase of the relative level of compounds containing carbonyl groups (in cortex as well as multiform and molecular cells of the hippocampal formation) as well as the decrease of the relative content of lipids and their structural changes (in white matter). What is more, the surface of the internal capsule (structure of the white matter) determined for this age group was smaller in animals subjected to prenatal KD exposure. The observed changes seem to arise from the elevated exposition to ketone bodies during a fetus life and the disturbance of lipid metabolism after prenatal exposure to the KD. These changes may be also associated with the processes of compensation of mother organism, which slowly began to make up for the deficiencies in carbohydrates postpartum.

Impact of Maternal Ketogenic Diet on NLRP3 Inflammasome Response in the Offspring Brain

The effects of maternal diet on the neuroimmune responses of the offspring remain to be elucidated. We investigated the impact of maternal ketogenic diet (KD) on the NLRP3 inflammasome response in the offspring's brain. C57BL/6 female mice were randomly allocated into standard diet (SD) and ketogenic diet (KD) groups for 30 days. After mating, the presence of sperm in the vaginal smear was considered day 0 of pregnancy, and female mice continued their respective diets during pregnancy and the lactation period. Following birth, pups were further allocated into two groups and given either LPS or intraperitoneal saline on postnatal (PN) days 4, 5 and 6; they were sacrificed on PN11 or PN21. Neuronal densities were significantly lower globally in the KD group when compared to the SD group at PN11. Neuronal density in the prefrontal cortex (PFC) and dentate gyrus (DG) regions were also significantly lower in the KD group when compared to the SD group at PN21. Following administration of LPS, the decrease in the neuronal count was more prominent in the SD group when compared to the KD group in the PFC and DG regions at PN11 and PN21. NLRP3 and IL-1β were higher in the KD group than in the SD group at PN21 in the PFC, CA1 and DG regions, and were significantly lower in the DG region of the KD group especially when compared to the SD group following LPS. Results of our study reveal that maternal KD negatively affects the offspring's brain in the mouse model. The effects of KD exhibited regional variations. On the other hand, in the presence of KD exposure, NLRP3 expression after LPS injection was lower in the DG and CA1 areas but not in the PFC when compared to SD group. Further experimental and clinical studies are warranted to elucidate the molecular mechanisms underlying the impact of antenatal KD exposure and regional discrepancies on the developing brain.

Intermittent fasting with ketogenic diet: A combination approach for management of chronic diseases

Intermittent Fasting (IF) is the consumption of food and drinks within a defined time, while the ketogenic diet (KD) switches the metabolism from glucose to fats. Continuation of intermittent fasting leads to the generation of ketones, the exact mechanism for a ketogenic diet. This article discusses the types of IF and KD, the monitoring required, and the mechanisms underlying IF and KD, followed by disorders in which the combination strategy could be applied. The strategies for successfully applying combination therapy are included, along with recommendations for the primary care physicians (PCP) which could serve as a handy guide for patient management. This opinion article could serve as the baseline for future clinical studies since there is an utmost need for developing new wholesome strategies for managing chronic disorders.

Impact of Prenatal Exposure to Maternal Diabetes and High-Fat Diet on Postnatal Myocardial Ketone Body Metabolism in Rats

Infants exposed to diabetic pregnancy are at higher risk of cardiomyopathy at birth and early onset cardiovascular disease (CVD) as adults. Using a rat model, we showed how fetal exposure to maternal diabetes causes cardiac disease through fuel-mediated mitochondrial dysfunction, and that a maternal high-fat diet (HFD) exaggerates the risk. Diabetic pregnancy increases circulating maternal ketones which can have a cardioprotective effect, but whether diabetes-mediated complex I dysfunction impairs myocardial metabolism of ketones postnatally remains unknown. The objective of this study was to determine whether neonatal rat cardiomyocytes (NRCM) from diabetes- and HFD-exposed offspring oxidize ketones as an alternative fuel source. To test our hypothesis, we developed a novel ketone stress test (KST) using extracellular flux analyses to compare real-time ß-hydroxybutyrate (βHOB) metabolism in NRCM. We also compared myocardial expression of genes responsible for ketone and lipid metabolism. NRCM had a dose-dependent increase in respiration with increasing concentrations of βHOB, demonstrating that both control and combination exposed NRCM can metabolize ketones postnatally. Ketone treatment also enhanced the glycolytic capacity of combination exposed NRCM with a dose-dependent increase in the glucose-mediated proton efflux rate (PER) from CO2 (aerobic glycolysis) alongside a decreased reliance on PER from lactate (anaerobic glycolysis). Expression of genes responsible for ketone body metabolism was higher in combination exposed males. Findings demonstrate that myocardial ketone body metabolism is preserved and improves fuel flexibility in NRCM from diabetes- and HFD-exposed offspring, which suggests that ketones might serve a protective role in neonatal cardiomyopathy due to maternal diabetes.

Low-Carbohydrate High-Fat Diet: A SWOC Analysis

Insulin resistance (IR) plays a role in the pathogenesis of many diseases, such as type 2 diabetes mellitus, cardiovascular disease, non-alcoholic fatty liver disease, obesity, and neurodegenerative diseases, including Alzheimer's disease. The ketogenic diet (KD) is a low-carbohydrate/high-fat diet that arose in the 1920s as an effective treatment for seizure control. Since then, the KD has been studied as a therapeutic approach for various IR-related disorders with successful results. To date, the use of the KD is still debatable regarding its safety. Some studies have acknowledged its usefulness, while others do not recommend its long-term implementation. In this review, we applied a SWOC (Strengths, Weaknesses, Opportunities, and Challenges) analysis that revealed the positive, constructive strengths of the KD, its potential complications, different conditions that can make used for it, and the challenges faced by both physicians and subjects throughout a KD. This SWOC analysis showed that the KD works on the pathophysiological mechanism of IR-related disorders such as chronic inflammation, oxidative stress and mitochondrial stress. Furthermore, the implementation of the KD as a potential adjuvant therapy for many diseases, including cancer, neurodegenerative disorders, polycystic ovary syndrome, and pain management was proven. On the other hand, the short and long-term possible undesirable KD-related effects, including nutritional deficiencies, growth retardation and nephrolithiasis, should be considered and strictly monitored. Conclusively, this review provides a context for decision-makers, physicians, researchers, and the general population to focus on this dietary intervention in preventing and treating diseases. Moreover, it draws the attention of scientists and physicians towards the opportunities and challenges associated with the KD that requires attention before KD initiation.

Using a Very Low Energy Diet to Achieve Substantial Preconception Weight Loss in Women with Obesity: A Review of the Safety and Efficacy

Obesity in women of reproductive age is common. Emerging evidence suggests that maternal obesity not only increases the risk of adverse pregnancy outcomes but also has an enduring impact on the metabolic health of the offspring. Given this, management of obesity prior to pregnancy is critically important. Almost all international guidelines suggest that women with obesity should aim to achieve weight loss prior to pregnancy. However, current pre-conception weight loss therapies are sub-optimal. Lifestyle modification typically results in modest weight loss. This may assist fertility but does not alter pregnancy outcomes. Bariatric surgery results in substantial weight loss, which improves pregnancy outcomes for the mother but may be harmful to the offspring. Alternative approaches to the management of obesity in women planning pregnancy are needed. Very low energy diets (VLEDs) have been proposed as a possible tool to assist women with obesity achieve weight loss prior to conception. While VLEDs can induce substantial and rapid weight loss, there are concerns about the impact of rapid weight loss on maternal nutrition prior to pregnancy and about inadvertent exposure of the early fetus to ketosis. The purpose of this review is to examine the existing literature regarding the safety and efficacy of a preconception VLED program as a tool to achieve substantial weight loss in women with obesity.

β-hydroxybutyrate reduces blastocyst viability via trophectoderm-mediated metabolic aberrations in mice

STUDY QUESTION

What is the effect of the ketone β-hydroxybutyrate (βOHB) on preimplantation mouse embryo development, metabolism, epigenetics and post-transfer viability?

SUMMARY ANSWER

In vitro βOHB exposure at ketogenic diet (KD)-relevant serum concentrations significantly impaired preimplantation mouse embryo development, induced aberrant glycolytic metabolism and reduced post-transfer fetal viability in a sex-specific manner.

WHAT IS KNOWN ALREADY

A maternal KD in humans elevates gamete and offspring βOHB exposure during conception and gestation, and in rodents is associated with an increased time to pregnancy, and altered offspring organogenesis, post-natal growth and behaviour, suggesting a developmental programming effect. In vitro exposure to βOHB at supraphysiological concentrations (8–80 mM) perturbs preimplantation mouse embryo development.

STUDY DESIGN, SIZE, DURATION

A mouse model of embryo development and viability was utilized for this laboratory-based study. Embryo culture media were supplemented with βOHB at KD-relevant concentrations, and the developmental competence, physiology, epigenetic state and post-transfer viability of in vitro cultured βOHB-exposed embryos was assessed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Mouse embryos were cultured in vitro with or without βOHB at concentrations representing serum levels during pregnancy (0.1 mM), standard diet consumption (0.25 mM), KD consumption (2 mM) and diabetic ketoacidosis (4 mM). The impact of βOHB exposure on embryo development (blastocyst formation rate, morphokinetics and blastocyst total, inner cell mass and trophectoderm (TE) cell number), physiology (redox state, βOHB metabolism, glycolytic metabolism), epigenetic state (histone 3 lysine 27 β-hydroxybutyrylation, H3K27bhb) and post-transfer viability (implantation rate, fetal and placental development) was assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

All βOHB concentrations tested slowed embryo development (P < 0.05), and βOHB at KD-relevant serum levels (2 mM) delayed morphokinetic development, beginning at syngamy (P < 0.05). Compared with unexposed controls, βOHB exposure reduced blastocyst total and TE cell number (≥0.25 mM; P < 0.05), reduced blastocyst glucose consumption (2 mM; P < 0.01) and increased lactate production (0.25 mM; P < 0.05) and glycolytic flux (0.25 and 2 mM; P < 0.01). Consumption of βOHB by embryos, mediated via monocarboxylate transporters, was detected throughout preimplantation development. Supraphysiological (20 mM; P < 0.001), but not physiological (0.25–4 mM) βOHB elevated H3K27bhb levels. Preimplantation βOHB exposure at serum KD levels (2 mM) reduced post-transfer viability. Implantation and fetal development rates of βOHB-treated embryos were 50% lower than controls (P < 0.05), and resultant fetuses had a shorter crown-rump length (P < 0.01) and placental diameter (P < 0.05). A strong sex-specific effect of βOHB was detected, whereby female fetuses from βOHB-treated embryos weighed less (P < 0.05), had a shorter crown-rump length (P < 0.05), and tended to have accelerated ear development (P < 0.08) compared with female control fetuses.

LIMITATIONS, REASONS FOR CAUTION

This study only assessed embryo development, physiology and viability in a mouse model utilizing in vitro βOHB exposure; the impact of in vivo exposure was not assessed. The concentrations of βOHB utilized were modelled on blood/serum levels as the true oviduct and uterine concentrations are currently unknown.

WIDER IMPLICATIONS OF THE FINDINGS

These findings indicate that the development, physiology and viability of mouse embryos is detrimentally impacted by preimplantation exposure to βOHB within a physiological range. Maternal diets which increase βOHB levels, such as a KD, may affect preimplantation embryo development and may therefore impair subsequent viability and long-term health. Consequently, our initial observations warrant follow-up studies in larger human populations. Furthermore, analysis of βOHB concentrations within human and rodent oviduct and uterine fluid under different nutritional states is also required.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the University of Melbourne and the Norma Hilda Schuster (nee Swift) Scholarship. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Continuous Ketone Monitoring Consensus Report 2021

This article is the work product of the Continuous Ketone Monitoring Consensus Panel, which was organized by Diabetes Technology Society and met virtually on April 20, 2021. The panel consisted of 20 US-based experts in the use of diabetes technology, representing adult endocrinology, pediatric endocrinology, advanced practice nursing, diabetes care and education, clinical chemistry, and bioengineering. The panelists were from universities, hospitals, freestanding research institutes, government, and private practice. Panelists reviewed the medical literature pertaining to ten topics: (1) physiology of ketone production, (2) measurement of ketones, (3) performance of the first continuous ketone monitor (CKM) reported to be used in human trials, (4) demographics and epidemiology of diabetic ketoacidosis (DKA), (5) atypical hyperketonemia, (6) prevention of DKA, (7) non-DKA states of fasting ketonemia and ketonuria, (8) potential integration of CKMs with pumps and automated insulin delivery systems to prevent DKA, (9) clinical trials of CKMs, and (10) the future of CKMs. The panelists summarized the medical literature for each of the ten topics in this report. They also developed 30 conclusions (amounting to three conclusions for each topic) about CKMs and voted unanimously to adopt the 30 conclusions. This report is intended to support the development of safe and effective continuous ketone monitoring and to apply this technology in ways that will benefit people with diabetes.

Periconceptional 1,3-butanediol supplementation suppresses the superimposed preeclampsia-like phenotype in the Dahl salt-sensitive rat

Preeclampsia is a hypertensive pregnancy disorder with no treatment beyond management of symptoms and delivery of the fetus and placenta. Chronic hypertension increases the risk of developing superimposed preeclampsia. Previous reports showed that 1,3-butanediol attenuates hypertension in rodents; however, the therapeutic potential of 1,3-butanediol for the prevention of preeclampsia has not been investigated. This study tested the hypothesis that attenuating hypertension before pregnancy and through the placentation period via 1,3-butanediol prevents the onset of preeclampsia in female Dahl salt-sensitive (SS/Jr) rats. Female Dahl SS/Jr rats were divided into two groups: 1,3-butanediol treated (20% via drinking water) and control (ad libitum water). Both groups were maintained on low-salt rodent chow (Teklad 7034, 0.3% NaCl; n = 8/group). Animals were treated with 1,3-butanediol for 7 wk (baseline), mated, and treated through day 12 of pregnancy. 1,3-Butanediol treatment increased plasma β-hydroxybutyrate (metabolite of 1,3-butanediol) that negatively correlated with maternal body weight in late pregnancy. Mean arterial pressure was lower in the treated group at baseline, early, and mid pregnancy, but no difference was observed in late pregnancy after treatment ended. Uterine artery resistance index (UARI) was reduced in the treated dams. No adverse fetal effects were observed, and there were no differences in pup weight or length. Placentas from treated dams had decreased vascular endothelial growth factor levels as well as decreased placental basal zone thickness and increased labyrinth zone thickness. These findings support the therapeutic role of physiological ketosis via 1,3-butanediol as a potential therapeutic approach for managing chronic hypertension, thereby preventing and mitigating adverse pregnancy outcomes associated with preeclampsia.NEW & NOTEWORTHY A ketogenic diet or increased β-hydroxybutyrate levels can reduce hypertension, but the potential of 1,3-butanediol, a β-hydroxybutyrate precursor, for treatment of preeclampsia is unknown. We hypothesized that attenuating hypertension before and during pregnancy via 1,3-butanediol prevents preeclampsia in Dahl Salt-sensitive rats. 1,3-Butanediol significantly lowered blood pressure and improved uterine artery resistance with no observable adverse fetal effects. Physiological ketosis via 1,3-butanediol may be a potential therapeutic approach for managing hypertension and mitigating adverse pregnancy outcomes.

Ketogenic diet impairs neurological development of neonatal rats and affects biochemical composition of maternal brains: evidence of functional recovery in pups

The ketogenic diet (KD) is a type of diet in which the intake of fats significantly increases at the cost of carbohydrates while maintaining an adequate amount of proteins. This kind of diet has been successfully used in clinical therapies of drug-resistant epilepsy, but there is still insufficient evidence on its safety when used in pregnancy. To assess KD effects on the course of gestation and fetal development, pregnant females were fed with: (i) KD during pregnancy and lactation periods (KD group), (ii) KD during pregnancy replaced with ND from the day 2 postpartum (KDND group) and (iii) normal diet alone (ND group). The body mass, ketone and glucose blood levels, and food intake were monitored. In brains of KD-fed females, FTIR biochemical analyses revealed increased concentrations of lipids and ketone groups containing molecules. In offspring of these females, significant reduction of the body mass and delays in neurological development were detected. However, replacement of KD with ND in these females at the beginning of lactation period led to regainment of the body mass in their pups as early as on the postnatal day 14. Moreover, the vast majority of our neurological tests detected functional recovery up to the normal level. It could be concluded that the ketogenic diet undoubtedly affects the brain of pregnant females and impairs the somatic and neurological development of their offspring. However, early postnatal withdrawal of this diet may initiate compensatory processes and considerable functional restitution of the nervous system based on still unrecognized mechanisms.

Practical Considerations for Ketogenic Diet in Adults With Super-Refractory Status Epilepticus

Purpose of Review

Ketogenic diet therapy can be used as an adjuvant treatment of super-refractory status epilepticus (SRSE). However, the drug and metabolic interactions with concomitant treatments present a challenge for clinicians. In this review, we focus on the practical considerations of implementing ketogenic dietary therapy in the acute setting, including the dietary composition, potential drug-diet interactions, and monitoring during ketogenic treatment.

Recent Findings

This report describes the ketogenic diet therapy protocol implemented for the treatment of SRSE and a review of the current evidence to support clinical practice.

Summary

The control of SRSE is critical in reducing morbidity and mortality. There is emerging evidence that ketogenic diet may be a safe and effective treatment option for these patients.

Decreased ovarian reserve and ovarian morphological alterations in female rat offspring exposed to a ketogenic maternal diet

OBJECTIVE

This study evaluates the effects of a ketogenic diet on morphology and follicle reserve.

METHOD

Sixteen Sprague-Dawley rats were randomized into two groups: standard diet group (n=8) and ketogenic diet group (n=8). Rats were time mated. Dams were permitted to deliver spontaneously. The animals were monitored for the onset of puberty. All the rats were weighed and anesthetized, serum anti-Müllerian hormone level was measured, and the oviducts were removed. The morphological characteristics of follicles were determined and total ovarian volumes were calculated.

RESULTS

The mean ovarian volume was statistically significantly lower in the ketogenic diet group compared to the standard diet group (14.41±0.99 mm3 versus 18.89±1.28 mm3) (p=0.000). The mean number of antral follicles was 13.63±1.80 in the standard diet group and 4.462±0.760 in the ketogenic diet group. The mean ovarian weight of the ketogenic diet group was significantly lower than that of the standard diet group (0.42±0.06 g versus 0.815±107 g). The mean anti-Müllerian hormone levels were significantly higher in the standard diet group compared to the ketogenic diet group (1.023±4.75 ng/mL versus 0.69±0.07 ng/mL) (p=0.000). The mean percentage of staining of Ki-67 was 35.28±4.75 in the standard diet group and 16.98±3.33 in the ketogenic diet group (p=0.000).

CONCLUSION

Maternal ketogenic diet reduces ovarian follicular reserve in female offspring and has important implications for maintaining reproductive potential at a population level.

Practical considerations of dietary therapies for epilepsy in adults

Despite the increasing number of anti-seizure medications becoming available, the proportion of patients with drug-resistant epilepsy remains unchanged. Dietary therapy for epilepsy is well-established practice in paediatric care, but relatively underutilised in adults. Recently, international recommendations have been published to guide the treatment of adults receiving dietary therapy for epilepsy.

This review focuses on the specific aspects of care unique to the management of adults receiving dietary therapy for epilepsy, including patient selection, diet composition, initiation, monitoring and cessation of dietary treatment. We emphasise the need for a multidisciplinary team approach with appropriately trained neurologists and dietitians to provide holistic care while the patients are receiving dietary therapy. Future research should focus on the optimal diet composition and meeting the psychosocial needs of adults with epilepsy to maximise efficacy and adherence to dietary treatment.

Transcriptome analysis of two structurally related flavonoids; Apigenin and Chrysin revealed hypocholesterolemic and ketogenic effects in mouse embryonic fibroblasts

There is no known single therapeutic drug for treating hypercholesterolemia that comes with negligible systemic side effects. In the current study, using next generation RNA sequencing approach in mouse embryonic fibroblasts we discovered that two structurally related flavonoid compounds. Apigenin and Chrysin exhibited moderate blocking ability of multiple transcripts that regulate rate limiting enzymes in the cholesterol biosynthesis pathway. The observed decrease in cholesterol biosynthesis pathway correlated well with an increase in transcripts involved in generation and trafficking of ketone bodies as evident by the upregulation of Bdh1 and Slc16a6 transcripts. The hypocholesterolemic potential of Apigenin and Chrysin at higher concentrations along with their ability to generate ketogenic substrate especially during embryonic stage is useful or detrimental for embryonic health is not clear and still debatable. Our study will serve as a steppingstone to further the investigation in whole animal studies and also in translating this knowledge to human studies.

βOHB Protective Pathways in Aralar-KO Neurons and Brain: An Alternative to Ketogenic Diet

Aralar/AGC1/Slc25a12, the mitochondrial aspartate-glutamate carrier expressed in neurons, is the regulatory component of the NADH malate-aspartate shuttle. AGC1 deficiency is a neuropediatric rare disease characterized by hypomyelination, hypotonia, developmental arrest, and epilepsy. We have investigated whether β-hydroxybutyrate (βOHB), the main ketone body (KB) produced in ketogenic diet (KD), is neuroprotective in aralar-knock-out (KO) neurons and mice. We report that βOHB efficiently recovers aralar-KO neurons from deficits in basal-stimulated and glutamate-stimulated respiration, effects requiring βOHB entry into the neuron, and protects from glutamate excitotoxicity. Aralar-deficient mice were fed a KD to investigate its therapeutic potential early in development, but this approach was unfeasible. Therefore, aralar-KO pups were treated without distinction of gender with daily intraperitoneal injections of βOHB during 5 d. This treatment resulted in a recovery of striatal markers of the dopaminergic system including dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC)/DA ratio, and vesicular monoamine transporter 2 (VMAT2) protein. Regarding postnatal myelination, myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) myelin proteins were markedly increased in the cortices of βOHB-treated aralar-KO mice. Although brain Asp and NAA levels did not change by βOHB administration, a 4-d βOHB treatment to aralar-KO, but not to control, neurons led to a substantial increase in Asp (3-fold) and NAA (4-fold) levels. These results suggest that the lack of increase in brain Asp and NAA is possibly because of its active utilization by the aralar-KO brain and the likely involvement of neuronal NAA in postnatal myelination in these mice. The effectiveness of βOHB as a therapeutic treatment in AGC1 deficiency deserves further investigation.SIGNIFICANCE STATEMENT Aralar deficiency induces a fatal phenotype in humans and mice and is associated with impaired neurodevelopment, epilepsy, and hypomyelination. In neurons, highly expressing aralar, its deficiency causes a metabolic blockade hampering mitochondrial energetics and respiration. Here, we find that βOHB, the main metabolic product in KD, recovers defective mitochondrial respiration bypassing the metabolic failure in aralar-deficient neurons. βOHB oxidation in mitochondria boosts the synthesis of cytosolic aspartate (Asp) and NAA, which is impeded by aralar deficiency, presumably through citrate-malate shuttle. In aralar-knock-out (KO) mice, βOHB recovers from the drastic drop in specific dopaminergic and myelin markers. The βOHB-induced myelin synthesis occurring together with the marked increment in neuronal NAA synthesis supports the role of NAA as a lipid precursor during postnatal myelination.

Ketogenic therapy in neurodegenerative and psychiatric disorders: From mice to men

Ketogenic diet is a low carbohydrate and high fat diet that has been used for over 100 years in the management of childhood refractory epilepsy. More recently, ketogenic diet has been investigated for a number of metabolic, neurodegenerative and neurodevelopmental disorders. In this comprehensive review, we critically examine the potential therapeutic benefits of ketogenic diet and ketogenic agents on neurodegenerative and psychiatric disorders in humans and translationally valid animal models. The preclinical literature provides strong support for the efficacy of ketogenic diet in a variety of diverse animal models of neuropsychiatric disorders. However, the evidence from clinical studies, while encouraging, particularly in Alzheimer's disease, psychotic and autism spectrum disorders, is limited to case studies and small pilot trials. Firm conclusion on the efficacy of ketogenic diet in psychiatric disorders cannot be drawn due to the lack of randomised, controlled clinical trials. The potential mechanisms of action of ketogenic therapy in these disorders with diverse pathophysiology may include energy metabolism, oxidative stress and immune/inflammatory processes. In conclusion, while ketogenic diet and ketogenic substances hold promise pre-clinically in a variety of neurodegenerative and psychiatric disorders, further studies, particularly randomised controlled clinical trials, are warranted to better understand their clinical efficacy and potential side effects.

The ketogenic diet all grown up-Ketogenic diet therapies for adults

The use of ketogenic diet therapies (KDT) in adults has expanded in the last two decades and has been accompanied by a surge of new retrospective as well as prospective studies evaluating its efficacy in adults with epilepsy. In this review article, we will highlight the recent clinical trials and advances in the use of the ketogenic diet therapy (KDT) in adult patients with epilepsy. We will analyze the responder rate in regard to the epilepsy syndrome (focal vs generalized) to identify adults who are optimal to consider for KDT. In addition to its role in treating patients with chronic epilepsy, we will explore the emerging use of the KDT in the critical care setting in adults with refractory and super-refractory status epilepticus as well as other neurologic disorders. Finally, we will discuss special considerations for the use of KDT in adults with epilepsy including its potential long-term effects on bone and cardiovascular health, and its use in pregnancy.

Effect of Elevated Ketone Body on Maternal and Infant Outcome of Pregnant Women with Abnormal Glucose Metabolism During Pregnancy

Ketone bodies are one of the products of fat metabolism which can be used as an alternative energy source for the human body in states of glucose deficiency. Normal pregnant women may develop ketosis due to physiological changes during pregnancy, while pregnant women with abnormal glucose metabolism are more likely to develop ketosis due to abnormal insulin secretion. Animal experiments and clinical studies have shown that exposure to high-ketone environments during pregnancy is closely related to adverse maternal and infant outcomes. However, there is no unified conclusion on whether ketone bodies should be routinely monitored during pregnancy. This review summarizes the existing studies on ketone body levels and pregnancy outcomes in the case of abnormal blood glucose during pregnancy, elaborates the current guidelines on the level of ketone bodies, provides the detection and treatment of ketosis in pregnant women with abnormal blood glucose in the clinical practice.

Evidenced-Based Nutrition for Gestational Diabetes Mellitus

PURPOSE OF REVIEW

To review the latest evidence for dietary interventions for treatment of gestational diabetes (GDM).

RECENT FINDINGS

High-quality systematic reviews demonstrate no major advantages between the low-carbohydrate or calorie-restricted diets. However, the low glycemic index (GI) diet, characterized by intake of high-quality, complex carbohydrates, demonstrated lower insulin use and reduced risk of macrosomia in multiple reviews. Recent evidence suggests the Mediterranean diet is safe in pregnancy, though trials are needed to determine its efficacy over conventional dietary advice. Currently, there are insufficient data to support the safety of the ketogenic diet for the treatment of GDM. The low GI diet may improve maternal and neonatal outcomes in GDM. The liberalized carbohydrate intake is less restrictive, culturally adaptable, and may improve long-term maternal adherence. Further research is needed to establish the optimal, most sustainable, and most acceptable medical nutrition therapy for management of women with GDM.

Physicians' attitudes and views regarding religious fasting during pregnancy and review of the literature

Many patients worldwide seek medical advice regarding safety of fasting during pregnancy. This issue lacks high quality evidence, which makes giving medical advice challenging. To aid decision making on this subject we performed an internet mediated survey to determine the expert opinion on this issue. The survey was answered by one hundred and eight obstetricians and gynecologists (OB/GYN). The questions were aimed at the content of the medical advice given to pregnant patients on Ramadan (for Muslim patients) and Yom Kippur (for Jewish patients) fasts. For both fasts, most physicians recommended against fasting on the second or third trimester, while fasting on the first trimester was controversial. Differences were found between medical advices provided by physicians according to their demographical characteristics. Regarding Ramadan fast, senior specialists were more lenient about fasting than younger specialists (62% and 35%, respectively, p = 0.01). As to Yom Kippur fast, religious and traditional physicians were more likely to permit fasting compared to their secular colleagues (53% and 25%, respectively, p = 0.01). Additionally, a comprehensive literature review was conducted revealing possible adverse maternal and fetal outcomes of fasting; however the risk for long term clinical complications is yet to be defined.

Health consequences for mother and baby of substantial pre-conception weight loss in obese women: study protocol for a randomized controlled trial

BACKGROUND

Current guidelines for the management of obesity in women planning pregnancy suggest lifestyle modification before conception. However, there is little evidence that lifestyle modification alters pregnancy outcomes. Bariatric surgery results in significant weight loss. This appears to reduce the risk of adverse pregnancy outcomes for the mother but may increase the risk of adverse outcomes for the infant. In order to reduce the risks of obesity-related adverse pregnancy outcomes for both mother and offspring, alternative approaches to the management of obesity in women planning pregnancy are needed.

METHODS/DESIGN

This study, a two-arm, parallel group, randomized control trial, will be conducted at the Metabolic Disorders Centre, University of Melbourne. This trial will recruit 164 women aged 18-38 years with a body mass index of 30-55 kg/m² who plan to conceive in the next 6-12 months. Women will be randomized to one of two 12-week interventions (Group A and Group B). Group A will aim for modest weight loss (MWL; ≤ 3% body weight) using a hypocaloric diet. Group B will aim for substantial weight loss (SWL; 10-15% body weight) using a modified very low energy diet (VLED) program. All participants will be asked to comply with National Health and Medical Research Council (NHMRC) guidelines for exercise and will be provided with standard pre-pregnancy advice according to Royal Australian and New Zealand College of Obstetrics and Gynaecology guidelines. All participants will then be observed for the subsequent 12 months. If pregnancy occurs within the 12-month follow-up period, data on weight and metabolic status of the mother, and pregnancy outcomes of mother and offspring will be recorded. The primary outcome is maternal fasting plasma glucose at 26-28 weeks' gestation, given that this is known to correlate with pregnancy outcomes. Time to conception, live birth rate, gestational weight gain, and a composite of adverse pregnancy outcomes for mother and baby will comprise the secondary outcomes.

DISCUSSION

There is increasing emphasis on obese women losing weight before conception. To date, no randomized controlled trial has demonstrated an effective means of weight loss that results in improved pregnancy outcomes for both mother and baby. This study intends to determine if substantial pre-conception weight loss, achieved using a VLED, improves pregnancy outcomes for mother and baby when compared with standard care. This research will potentially change clinical care of an obese woman planning pregnancy.

TRIAL REGISTRATION

ANZCTR, 12,614,001,160,628 . Registered on 5 November 2014.

Gestational ketogenic diet programs brain structure and susceptibility to depression & anxiety in the adult mouse offspring

INTRODUCTION

The ketogenic diet (KD) has seen an increase in popularity for clinical and non-clinical purposes, leading to rise in concern about the diet's impact on following generations. The KD is known to have a neurological effect, suggesting that exposure to it during prenatal brain development may alter neuro-anatomy. Studies have also indicated that the KD has an anti-depressant effect on the consumer. However, it is unclear whether any neuro-anatomical and/or behavioral changes would occur in the offspring and persist into adulthood.

METHODS

To fill this knowledge gap we assessed the brain morphology and behavior of 8-week-old young-adult CD-1 mice, who were exposed to the KD in utero, and were fed only a standard-diet (SD) in postnatal life. Standardized neuro-behavior tests included the Open-Field, Forced-Swim, and Exercise Wheel tests, and were followed by post-mortem Magnetic Resonance Imaging (MRI) to assess brain anatomy.

RESULTS

The adult KD offspring exhibit reduced susceptibility to anxiety and depression, and elevated physical activity level when compared with controls exposed to the SD both in utero and postnatally. Many neuro-anatomical differences exist between the KD offspring and controls, including, for example, a cerebellar volumetric enlargement by 4.8%, a hypothalamic reduction by 1.39%, and a corpus callosum reduction by 4.77%, as computed relative to total brain volume.

CONCLUSIONS

These results suggest that prenatal exposure to the KD programs the offspring neuro-anatomy and influences their behavior in adulthood.

Automated pipeline for anatomical phenotyping of mouse embryos using micro-CT

The International Mouse Phenotyping Consortium (IMPC) plans to phenotype 20,000 single-gene knockout mice to gain an insight into gene function. Approximately 30% of these knockout mouse lines will be embryonic or perinatal lethal. The IMPC has selected three-dimensional (3D) imaging to phenotype these mouse lines at relevant stages of embryonic development in an attempt to discover the cause of lethality using detailed anatomical information. Rate of throughput is paramount as IMPC production centers have been given the ambitious task of completing this phenotyping project by 2021. Sifting through the wealth of data within high-resolution 3D mouse embryo data sets by trained human experts is infeasible at this scale. Here, we present a phenotyping pipeline that identifies statistically significant anatomical differences in the knockout, in comparison with the wild type, through a computer-automated image registration algorithm. This phenotyping pipeline consists of three analyses (intensity, deformation, and atlas based) that can detect missing anatomical structures and differences in volume of whole organs as well as on the voxel level. This phenotyping pipeline was applied to micro-CT images of two perinatal lethal mouse lines: a hypomorphic mutation of the Tcf21 gene (Tcf21-hypo) and a knockout of the Satb2 gene. With the proposed pipeline we were able to identify the majority of morphological phenotypes previously published for both the Tcf21-hypo and Satb2 mutant mouse embryos in addition to novel phenotypes. This phenotyping pipeline is an unbiased, automated method that highlights only those structural abnormalities that survive statistical scrutiny and illustrates them in a straightforward fashion.

Maternal glucocorticoid elevation and associated blood metabonome changes might be involved in metabolic programming of intrauterine growth retardation in rats exposed to caffeine prenatally

Our previous studies demonstrated that prenatal caffeine exposure causes intrauterine growth retardation (IUGR), fetuses are over-exposed to high levels of maternal glucocorticoids (GC), and intrauterine metabolic programming and associated metabonome alteration that may be GC-mediated. However, whether maternal metabonomes would be altered and relevant metabolite variations might mediate the development of IUGR remained unknown. In the present studies, we examined the dose- and time-effects of caffeine on maternal metabonome, and tried to clarify the potential roles of maternal GCs and metabonome changes in the metabolic programming of caffeine-induced IUGR. Pregnant rats were treated with caffeine (0, 20, 60 or 180 mg/kg·d) from gestational days (GD) 11 to 20, or 180 mg/kg·d caffeine from GD9. Metabonomes of maternal plasma on GD20 in the dose-effect study and on GD11, 14 and 17 in the time-course study were analyzed by ¹H nuclear magnetic resonance spectroscopy, respectively. Caffeine administration reduced maternal weight gains and elevated both maternal and fetal corticosterone (CORT) levels. A negative correlation between maternal/fetal CORT levels and fetal bodyweight was observed. The maternal metabonome alterations included attenuated metabolism of carbohydrates, enhanced lipolysis and protein breakdown, and amino acid accumulation, suggesting GC-associated metabolic effects. GC-associated metabolite variations (α/β-glucoses, high density lipoprotein-cholesterol, β-hydroxybutyrate) were observed early following caffeine administration. In conclusion, prenatal caffeine exposure induced maternal GC elevation and metabonome alteration, and maternal GC and relevant discriminatory metabolites might be involved in the metabolic programming of caffeine-induced IUGR.

A gestational ketogenic diet alters maternal metabolic status as well as offspring physiological growth and brain structure in the neonatal mouse

BACKGROUND

The use of the ketogenic diet (KD) among women of child-bearing age has been increasing, leading to increased interest in identifying the diet's suitability during gestation. To date, no studies have thoroughly investigated the effect of a gestational KD on offspring growth. Since ketones have been reported to play a role in cerebral lipid and myelin synthesis, it is particularly important to investigate the diet's impact on brain anatomy of the offspring.

METHODS

To fill this knowledge gap we imaged CD-1 mouse neonates whose mothers were fed either a standard diet (SD) or a KD prior to and during gestation. Images were collected at postnatal (P) 11.5 and 21.5 using Magnetic Resonance Imaging (MRI). Maternal metabolic status was also tracked during lactation, by following their body weight, blood glucose, ketone, cholesterol, and triglyceride concentrations.

RESULTS

The KD dams exhibit a significant reduction in maternal fertility and litter size, as well as a high risk of developing fatal ketoacidosis by mid-lactation. To increase survival of the KD dams and offspring, fostering of P2.5 pups (from both KD and SD litters) by SD-foster dams was carried out. This resulted in stabilization of blood ketones of the KD dams, and aversion of the fatal ketoacidosis. We also note a slower and smaller weight loss for the KD compared with the SD dams. The average fostered KD pup exhibits retarded growth by P21.5 compared with the average fostered SD pup. An anatomical comparison of their brains further revealed significant structural differences at P11.5, and particularly at P21.5. The KD brain shows a relative bilateral decrease in the cortex, fimbria, hippocampus, corpus callosum and lateral ventricle, but a relative volumetric enlargement of the hypothalamus and medulla.

CONCLUSION

A gestational ketogenic diet deleteriously affects maternal fertility and increases susceptibility to fatal ketoacidosis during lactation. Prenatal and early postnatal exposure to a ketogenic diet also results in significant alterations to neonatal brain structure, and results in retarded physiological growth. These alterations could be accompanied by functional and behavioural changes in later postnatal life.