Jennifer T Smilowitz

• PhD
• Assistant Professor of Cooperative Extension at University of California, Davis

Background Nutrition in the first 1000 days of life, from conception to age 2 years, plays a critical role in shaping offspring's physical and mental development, yet many families from underserved backgrounds suffer from nutrition inequity during this important stage of development. The objective of this study is to assess nutrition services and r...

In May of 2022, millions of U.S. parents encountered uncertainty in safely feeding their infants due to the infant formula shortage. Methods: An anonymous, electronic, cross-sectional, retrospective survey was used. Results: U.S. parents (n = 178) whose infants were ~10 weeks old during the shortage completed the survey. Of parents, 81% switched fo...

In May of 2022, millions of U.S. parents faced uncertainty in safely feeding their infants due to the infant formula shortage. Methods: An anonymous, electronic, cross-sectional, retrospective survey was used. Results: U.S. parents (n =187) whose infants were 10.2 weeks old during the short-age completed the survey. Eighty-one percent of parents sw...

Photo-based dietary assessment is becoming more feasible as artificial intelligence methods improve. However, advancement of these methods for dietary assessment in research settings has been hindered by the lack of an appropriate dataset against which to benchmark algorithm performance. We conducted the Surveying Nutrient Assessment with Photograp...

Background: In May of 2022, parents living in the United States experienced a dramatic infant formula shortage caused by supply chain issues and the recall of several infant formula products over contamination concerns. Methods: An anonymous, electronic, cross-sectional survey was designed to understand infant feeding practices, parental experie...

Human milk is universally recognized as the preferred food for infants during the first 6 mo of life because it provides not only essential and conditionally essential nutrients in necessary amounts but also other biologically active components that are instrumental in protecting, communicating important information to support, and promoting optima...

Background In May of 2022, parents living in the United States experienced a dramatic infant formula shortage caused by supply chain issues and the recent recall of several infant formula products over contamination concerns. Methods An anonymous, electronic, cross-sectional survey was designed to understand infant feeding practices, parental expe...

Objectives Photo-based dietary assessment methods are becoming more feasible as artificial intelligence methods improve. However, advancement of these methods to the level usable in nutrition studies has been hindered by the lack of a dataset against which to benchmark algorithm performance. Here, we introduce the Surveying Nutrient Assessment with...

The molecular complexity of the carbohydrates consumed by humans has been deceptively oversimplified due to a lack of analytical methods that possess the throughput, sensitivity, and resolution required to provide quantitative structural information. However, such information is becoming an integral part of understanding how specific glycan structu...

Bifidobacterium species are beneficial and dominant members of the breastfed infant gut microbiome; however, their health benefits are partially species-dependent. Here, we characterize the species and subspecies of Bifidobacterium in breastfed infants around the world to consider the potential impact of a historic dietary shift on the disappearanc...

Bifidobacterium are a beneficial and dominant member of the breast-fed infant gut microbiome. However, the health benefits of Bifidobacterium are partially species dependent. Here we characterize the species and subspecies of Bifidobacterium present in breastfed infants around the world. Across populations, three distinct patterns of Bifidobacteriu...

Background Human milk oligosaccharides (HMOs) are an abundant class of compounds found in human milk and have been linked to the development of the infant and specifically the brain, immune system, and gut microbiome. Objectives Advanced analytical methods were used to obtain relative quantitation of many structures in approximately 2000 samples f...

Streptococcus salivarius (S. salivarius) K12 supplementation has been found to reduce the risk of recurrent upper respiratory tract infections. Yet, studies have not reported the effect of supplementation on oral S. salivarius K12 levels or the salivary microbiome. This clinical trial was designed to determine how supplementation with S. salivarius...

Immune-microbe interactions early in life influence the risk of allergies, asthma, and other inflammatory diseases. Breastfeeding guides healthier immune-microbe relationships by providing nutrients to specialized microbes that in turn benefit the host’s immune system. Such bacteria have co-evolved with humans but are now increasingly rare in moder...

Recent studies have reported a dysfunctional gut microbiome in breastfed infants. Probiotics have been used in an attempt to restore the gut microbiome; however, colonization has been transient, inconsistent among individuals, or has not positively impacted the host’s gut. This is a 2-year follow-up study to a randomized controlled trial wherein 7-...

Immune-microbe interactions early in life influence an individual’s risk of developing allergies, asthma and some autoimmune disorders. Breastfeeding helps guide the development of healthy immune-microbe relationships, in part by providing nutrients to specialized microbes that in turn benefit the host and its developing immune system. Such bacteri...

Polysaccharides are the most abundant biomolecules in nature, but are the least understood in terms of their chemical structures and biological functions. Polysaccharides cannot be simply sequenced because they are often highly branched and lack a uniform structure. Furthermore, large polymeric structures cannot be directly analyzed by mass spectro...

Objectives Very little is known about dietary carbohydrate and intestinal microbe interactions during the introduction of solid foods in exclusively breastfed infants. The objective of the UC Davis IMiND study is to discover the relationships between plant-derived complementary foods commonly used in the early weaning period and the gut microbiome...

Objectives Streptococcus salivarius (S. salivarius) K12 supplementation in children and adults has been found to reduce the risk of recurrent pharyngitis, tonsillitis, otitis media caused by group A streptococci. The protection of S. salivarius K12 supplementation may in part result from its production of lantibiotic bacteriocins salivaricin A and...

Human milk oligosaccharides play a vital role in the development of the gut microbiome in the human infant. Although oligosaccharides derived from bovine milk (BMO) differ in content and profile with those derived from human milk (HMO), several oligosaccharide structures are shared between the species. BMO are commercial alternatives to HMO, but th...

Background: Infant gut dysbiosis, often associated with low abundance of bifidobacteria, is linked to impaired immune development and inflammation-a risk factor for increased incidence of several childhood diseases. We investigated the impact of B. infantis EVC001 colonization on enteric inflammation in a subset of exclusively breastfed term infan...

Background: Antibiotic-resistant (AR) bacteria are a global threat. AR bacteria can be acquired in early life and have long-term sequelae. Limiting the spread of antibiotic resistance without triggering the development of additional resistance mechanisms is of immense clinical value. Here, we show how the infant gut microbiome can be modified, res...

Secretory Immunoglobulin A (SIgA) is central to mucosal immunity: represents one of the main immunological mechanisms of defense against the potential attack of pathogens. During lactation SIgA is produced by plasmablasts in the mammary gland and is present in breast milk, playing a vital role in the passive immunity of the newborn. Interestingly,...

Objectives: Several seminal publications identify that Bifidobacterium longum subsp. infantis (B. infantis) has uniquely evolved to be the predominant strain in the breastfed infant gut; however, recent cohort studies indicate it is now far less abundant in infants born in industrialized nations, along with increased abundance of potentially patho...

Background: Proteins in human milk are essential and known to support the growth, development, protection, and health of the newborn. These proteins are highly modified by glycans that are currently being recognized as vital to protein structure, stability, function, and health of the intestinal mucosa. Although milk proteins have been studied, th...

CVD and associated metabolic diseases are linked to chronic inflammation, which can be modified by diet. The objective of the present study was to determine whether there is a difference in inflammatory markers, blood metabolic and lipid panels and lymphocyte gene expression in response to a high-fat dairy food challenge with or without milk fat gl...

Over half of all children with autism spectrum disorders (ASD) have gastrointestinal (GI) co-morbidities including chronic constipation, diarrhea, and irritable bowel syndrome. The severity of these symptoms has been correlated with the degree of GI microbial dysbiosis. The study objective was to assess tolerability of a probiotic (Bifidobacterium...

Proportion of hard and soft stools with treatment. Mean ± SD proportion of total recorded stools that were A) hard consistency (1 or 2 on Bristol Stool Scale) or B) soft consistency (6 or 7 on Bristol Stool Scale) based on stool log data (n = 8 for each group). Significant differences in means (p<0.05) are denoted by an asterisk. D123, days 1, 2 an...

Wilcoxon P-values gastrointestinal and behavioral questionnaire data. (DOCX)

Non-parametric statistics for stool consistency from stool log data. (DOCX)

The study of human milk has revealed the presence of complex human milk oligosaccharide (HMO) molecules, believed to help encourage formation and development of the infant's gut microbiome. HMOs function as prebiotics for beneficial bacteria, block attachment to pathogens, and interact directly with intestinal cells. Many bovine milk oligosaccharid...

The goal of this pilot study was to determine whether HDL composition, particularly key HDL‐associated glycoproteins, affects HDL immunomodulatory function. HDL were purified from healthy controls (n=13), subjects with metabolic syndrome (MetS) (n=13), and diabetic hemodialysis (HD) patients, who experienced an infectious hospitalization event with...

Objective To test for a difference in lymphocyte gene expression in response to a high fat dairy challenge with or without milk fat globule membrane (MFGM). Methods Data was analyzed from twenty individuals with BMI > 25.0 kg/m ² . On two separate occasions, each participant consumed a dairy‐based meal high in saturated fat with or without the add...

Historically, Bifidobacterium species were reported as abundant in the breastfed infant gut. However, recent studies in resource-rich countries show an increased abundance of taxa regarded as signatures of dysbiosis. It is unclear whether these differences are the product of genetics, geographic factors, or interventions such as formula feeding, an...

Triclosan is frequently used for its antimicrobial properties and has been detected in human serum, urine, and breast milk. Animal and molecular studies have shown that triclosan exerts a wide range of adverse health effects at both high (ppm) and low (ppb) concentrations. Since triclosan is of growing concern to human and environmental health, the...

Background: When human milk is unavailable, banked milk is recommended for feeding premature infants. Milk banks use processes to eliminate pathogens; however, variability among methods exists. Research aim: The aim of this study was to compare the macronutrient (protein, carbohydrate, fat, energy), immune-protective protein, and human milk oligosa...

The gut microbiome in early life plays an important role for long-term health and is shaped in large part by diet. Probiotics may contribute to improvements in health, but they have not been shown to alter the community composition of the gut microbiome. Here, we found that breastfed infants could be stably colonized at high levels by provision of...

Liquid chromatography–mass spectrometry (LC–MS) methods are most often used for untargeted metabolomics and lipidomics. However, methods have not been standardized as accepted ‘best practice’ documents, and reports lack harmonization with respect to quantitative data that enable inter-study comparisons. Researchers use a wide variety of high-resolu...

Scientific, technological, and economic progress over the last 100 years all but eradicated problems of widespread food shortage and nutrient deficiency in developed nations. But now society is faced with a new set of nutrition problems related to energy imbalance and metabolic disease, which require new kinds of solutions. Recent developments in t...

Background: When human milk is unavailable, banked milk is recommended for feeding premature infants. Milk banks use processes to eliminate pathogens; however, variability among methods exists. Research aim: The aim of this study was to compare the macronutrient (protein, carbohydrate, fat, energy), immune-protective protein, and human milk oligos...

Background: Historically, bifidobacteria were the dominant intestinal bacteria in breastfed infants. Still abundant in infants in developing nations, levels of intestinal bifidobacteria are low among infants in developed nations. Recent studies have described an intimate relationship between human milk and a specific subspecies of Bifidobacterium,...

Abstract Background Inflammation is associated with increased bone resorption; the role of inflammation in postprandial bone turnover has not been explored. Consumption of milk fat globule membrane (MFGM) reduces inflammation in animal models. This study aimed to measure postprandial changes in bone turnover after intake of high saturated fat test...

The goal of this pilot study was to determine whether HDL glycoprotein composition affects HDL’s immunomodulatory function. HDL were purified from healthy controls (n = 13), subjects with metabolic syndrome (MetS) (n = 13), and diabetic hemodialysis (HD) patients (n = 24). Concentrations of HDL-bound serum amyloid A (SAA), lipopolysaccharide bindin...

Mechanistic research suggests a unique evolutionary relationship between complex milk oligosaccharides and cognate bifidobacteria enriched in breast-fed infants. Bovine milk oligosaccharides (BMO) were recently identified as structurally and functionally similar to human milk oligosaccharides. The present single-blind three-way crossover study is t...

Human milk plays a substantial role in the child growth, development and determines their nutritional and health status. Despite the importance of the proteins and glycoproteins in human milk, very little quantitative information especially on their site-specific glycosylation is known. As more functions of milk proteins and other components contin...

The authors have drawn to the attention of the editor in chief of the journal errors in the following paper: O’Sullivan A, Farver M and Smilowitz JT. The Influence of Early Infant-Feeding Practices on the Intestinal Microbiome and Body Composition in Infants. Nutrition and Metabolic Insights. 2015;8(S1):1–9. doi: 10.4137/NMI.S29530.

Background The development of probiotics as therapies to cure or prevent disease lags far behind that of other investigational medications. Rigorously designed phase I clinical trials are nearly non-existent in the field of probiotic research, which is a contributing factor to this disparity. As a consequence, how to appropriately dose probiotics t...

Glycans in breast milk are abundant and found as either free oligosaccharides or conjugated to proteins and lipids. Free human milk oligosaccharides (HMOs) function as prebiotics by stimulating the growth of beneficial bacteria while preventing the binding of harmful bacteria to intestinal epithelial cells. Bacteria have adapted to the glycan-rich...

Introduction Plasma fatty acids are derived from preformed sources in the diet and de novo synthesis through the action of desaturase and elongase enzymes. Objective This study was designed to examine the elongation of gamma-linolenic acid (GLA, 18:3n6) into dihomo-gamma-linolenic acid (DGLA, 20:3n6) over an 8-h period using both targeted gas chrom...

Introduction—Plasma fatty acids are derived from preformed sources in the diet and de novo synthesis through the action of desaturase and elongase enzymes. Objective—This study was designed to examine the elongation of gamma-linolenic acid (GLA, 18:3n6) into dihomo-gamma-linolenic acid (DGLA, 20:3n6) over an 8-h period using both targeted gas chrom...

Abdominal obesity and metabolic syndrome (MS) are multifactorial conditions associated with increased risk of cardiovascular disease and type II diabetes mellitus. Previous work has demonstrated that the hemorheological profile is altered in patients with abdominal obesity and MS, as evidenced for example by increased whole blood viscosity. To date...

Number of cells observed in each experimental trial for OMA- participants. (DOCX)

Number of cells observed in each trial for OMA+ participants. (DOCX)

Metabolic syndrome (MS) defined by the American Heart Association as waist circumference (WC) > 40 inches for men and 35 inches for women, fasting plasma triglyceride (TG) ≥ 150 mg/dL, fasting plasma high density lipoprotein cholesterol (HDL-C) < 40 mg/dL for men and < 50 mg/dL for women, blood pressure (BP) ≥ 130/85 mmHg, and fasting glucose ≥ 100...

Methods Thirty‐six obese individuals were asked to fast for 12 hours prior to a baseline blood draw, on four separate visits separated by one to two weeks. Inflammatory markers, including serum amyloid A (SAA) and C‐reactive protein (CRP), cytokines, and adhesion markers were measured using multiplex assays. Data was analyzed in Microsoft Excel and...

Universally, for the first six months of life, Bifidobacterium longum subspecies infantis ( B. infantis ) is the dominant strain of intestinal bacteria in infants delivered vaginally and exclusively breastfed. In developed nations, infants delivered by cesarean section or vaginally have lower levels of intestinal B. infantis than infants born in de...

Meals high in SFA, particularly palmitate, are associated with postprandial inflammation and insulin resistance. Milk fat globule membrane (MFGM) has anti-inflammatory properties that may attenuate the negative effects of SFA-rich meals. Our objective was to examine the postprandial metabolic and inflammatory response to a high-fat meal composed of...

Dietary recommendations suggest decreased consumption of SFA to minimise CVD risk; however, not all foods rich in SFA are equivalent. To evaluate the effects of SFA in a dairy food matrix, as Cheddar cheese, v . SFA from a vegan-alternative test meal on postprandial inflammatory markers, a randomised controlled cross-over trial was conducted in twe...

Infant fecal samples are commonly studied to investigate the impacts of breastfeeding on the development of the microbiota and subsequent health effects. Comparisons of infants living in different geographic regions and environmental contexts are needed to aid our understanding of evolutionarily-selected milk adaptations. However, the preservation...

Despite many years of widespread international recommendations to support exclusive breastfeeding for the first six months of life, common hospital feeding and birthing practices do not coincide with the necessary steps to support exclusive breastfeeding. These common hospital practices can lead to the infant receiving formula in the first weeks of...

Metabolomics provides a valuable strategy for describing and annotating the structures, compositions, and functions of mammalian milk. Detailed analyses of the complex components of milk have revealed an unexpected diversity of glycans consisting of oligosaccharides, glycoproteins, and glycolipids, all of which help shape the intestinal environment...

Breast milk is a multifunctional biofluid that provides nutrients along with highly diverse non-nutritive bioactive components such as antibodies, glycans, bacteria, and immunomodulatory proteins. Research over the past decade has confirmed the essential role of breast milk bioactives in the establishment a healthy intestinal microbiota within the...

Human milk is the gold standard of nutrition for infants, providing both protective and essential nutrients. Although much is known about milk from mothers giving birth to term infants, less is known about milk from mothers giving birth to premature infants. In addition, little is known about the composition and diversity of small molecules in thes...

Individuals with inactive alleles of the fucosyltransferase 2 gene (FUT2; termed the ‘secretor’ gene) are common in many populations. Some members of the genus Bifidobacterium, common infant gut commensals, are known to consume 2′-fucosylated glycans found in the breast milk of secretor mothers. We investigated the effects of maternal secretor stat...

Biomarkers of bone turnover fluctuate over the course of a day; these fluctuations are exaggerated with food intake. The effect of foods with differing fatty acid profiles on this phenomenon is unknown. We compared bovine milk saturated fatty acids (SFA) to plant‐based SFA on post‐prandial bone metabolism in overweight/obese subjects. Adult subject...

Not all foods rich in SFA are equivalent and may vary in their effect on postprandial inflammation. Additionally, milk fat globule membrane (MFGM) is suggested to have anti‐inflammatory properties. To evaluate the effects of SFA from dairy (WC, whipping cream) vs. a plant source (P, palm oil) on postprandial inflammation markers with and without MF...

Milk has been well established as the optimal nutrition source for infants, yet there is still much to be understood about its molecular composition. Therefore, our objective was to develop and compare comprehensive milk proteomes for human and rhesus macaques to highlight differences in neonatal nutrition. We developed a milk proteomics technique...

Secretory immunoglobulin A (sIgA) is a major glycoprotein in milk and plays a key role in mediating immune protection of the gut mucosa. Although it is a highly glycosylated protein, its site-specific glycosylation and associated glycan micro-heterogeneity have still not been fully elucidated. In this study, the site-specific glycosylation of sIgA...

Hundreds of naturally occurring milk peptides are present in term human milk. Preterm milk is produced before complete maturation of the mammary gland, which could change milk synthesis and secretion processes within the mammary gland, leading to differences in protein expression and enzymatic activity, thereby resulting in an altered peptide profi...

Glycomic analysis is the comprehensive determination of glycan (oligosaccharide) structures with quantitative information in a biological sample. Rapid-throughput glycomics is complicated due to the lack of a template, which has greatly facilitated analysis in the field of proteomics. Furthermore, the large similarities in structures make fragmenta...

Proteomics of human milk has been used to identify the comprehensive cargo of proteins involved in immune and cellular function. Very little is known about the effects of gestational diabetes mellitus (GDM) on lactation and breast milk components. The objective of the current study was to examine the effect of GDM on the expression of proteins in t...