About

Professor Kelly S. Swanson is a faculty member in the Department of Animal Sciences and the Division of Nutritional Sciences at the University of Illinois. He holds the title of Kraft Heinz Company Endowed Professor in Human Nutrition and serves as the Director of the Division of Nutritional Sciences. His research focuses on comparative nutrition and nutrigenomics, integrating these fields to understand the interactions between diet, genetics, and health. As a leader in his department, he contributes to advancing knowledge in human and animal nutrition through his academic and research activities.

Research topics

• Biology
• Food science
• Internal medicine
• Medicine
• Microbiology
• Biochemistry
• Computer Science
• Animal science
• Chemistry
• Genetics
• Immunology
• Dentistry
• Biophysics
• Biotechnology
• Materials science
• Optics

Selected publications

• Trastuzumab Deruxtecan Is Active in Desmoplastic Small Round Cell Tumor

  JCO oncology advances. · 2026-01-01

  articleOpen access

  PURPOSE Desmoplastic small round cell tumor (DSRCT) is a rare sarcoma which remains almost universally fatal despite multimodality therapy. Human epidermal growth factor receptor 2 (HER2) has been identified as a potential therapeutic target prompting HER2-specific investigations and subsequent off-label treatment with fam-trastuzumab deruxtecan (T-DXd) in our DSRCT clinical cohort. METHODS Fifty-two and 61 DSRCT patient samples were analyzed by immunohistochemical (IHC) assays and RNAseq, respectively. In addition, 19 patients at a single institution with DSRCT in need of therapy underwent IHC testing and RNAseq when feasible and received off-label T-DXd (monotherapy [n = 14], alternating with another agent [n = 2], concomitantly in combination [n = 2]; measurable disease [n = 17], adjuvant setting [n = 2]). RESULTS HER2 expression levels by RNAseq were analyzed in the context of 346 patients with solid tumor and 23 histologies, with DSRCT having the third highest HER2 expression level overall and a median transcripts per million (TPM) expression level of 41.8 (range, 6.3-116.3). While TMA IHC analyses noted minimal HER2 IHC positivity using 4B5, IHC with clones 29D8 and CB11 uncovered 8.7- to 12.7-fold more HER2 reactivity, respectively. All 17 patients with measurable disease experienced clinical benefit (stable disease or partial response [PR]) with minimal toxicity. In addition, 9 of 17 patients achieved a RECIST PR (53% overall response rate). The response rate did not correlate with available IHC or RNAseq data, and some patients with no membranous IHC expression achieved PR. CONCLUSION These data show that T-DXd is active in DSRCT and support the planned biomarker-agnostic formal clinical trial with the Children's Oncology Group.

  PublisherDOI

• The effect of maropitant on sedation, propofol requirements, and cardiovascular function at induction of anesthesia in healthy cats.

  PubMed · 2026-04-01

  articleSenior author

  = 10) prior to anesthetic induction with propofol intravenously (IV). Cats were premedicated with butorphanol [0.4 mg/kg body weight (BW)] and alfaxalone [2 mg/kg BW intramuscularly (IM)]. Maropitant (1 mg/kg BW) or physiologic saline (0.1 mL/kg BW) was administered IV 10 min prior to anesthetic induction with propofol and subsequent orotracheal intubation. Sedation scores were recorded before premedication, after premedication, and 10 min after maropitant or saline administration. Propofol dose requirements to achieve orotracheal intubation were recorded. Heart rate (HR), respiratory rate (RR), and arterial blood pressures were measured before and after administration of maropitant or saline, after administration of propofol, and following intubation. Propofol dose requirements did not differ between groups, with mean ± standard deviation doses of 5.2 ± 2.1 mg/kg BW and 5.6 ± 1.3 mg/kg BW for maropitant and saline groups, respectively. Sedation scores and cardiorespiratory variables did not differ between groups at any timepoint. Maropitant administration prior to anesthetic induction with propofol did not affect sedation scores, propofol requirements, or cardiorespiratory variables.

  Publisher

• The effect of maropitant on sedation, propofol requirements, and cardiovascular function at induction of anesthesia in healthy cats

  PubMed Central · 2026-04-01

  articleOpen accessSenior author
  Publisher

• 304 Oral health indices and microbiota populations of adult cats consuming wet or dry diets.

  Journal of Animal Science · 2025-10-01

  articleOpen accessSenior author

  Abstract Oral microbiota play a critical role in feline periodontal disease, with wet foods often being associated with negative impacts on oral health. However, the oral microbial communities of cats remain underexplored. This study aimed to evaluate differences in the oral health indices and microbiota of cats fed a dry or wet diet. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. At baseline, all 20 healthy adult cats had their teeth cleaned and polished by a veterinarian. Cats were then randomly allotted to two treatments: dry diet (Cat Chow Complete with Real Chicken Dry Cat Food, Nestle Purina, St. Louis, MO) or wet diet (Friskies Pate Country Style Dinner Canned Cat Food, Nestle Purina, St. Louis, MO). After 28 weeks of diet consumption, sulfur-containing compound concentrations were measured using a halimeter, salivary pH was measured, plaque, calculus and gingivitis scores were assessed by a blinded veterinary, and supragingival and subgingival plaque samples were collected for microbiota analysis using 16S rRNA gene amplicon sequencing. Plaque microbiota data were evaluated using QIIME2. All other data were analyzed using the Mixed Models procedure of SAS, with P< 0.05 considered statistically significant. Cats fed the dry diet had lower calculus coverage and thickness than those fed the wet diet, but other health measures were not different between treatment groups. In supragingival plaque, cats fed the wet diet had lower alpha diversity measures (i.e., Observed features, Fisher index) than those consuming the dry diet. Additionally, there was a clear separation in microbiota communities between the dry- and wet-fed cats based on both unweighted and weighted UniFrac distances. The relative abundances of several bacterial taxa, including Synergistetes, Bacteroidota, Fretibacterium, Christensenellaceae R-7 group, Tannerella, Filifactor, and Bacteroides were more abundant in cats fed the wet diet. In contrast, the relative abundances of Proteobacteria, Patescibacteria, Campylobacter, Streptococcus, Bergeyella, Flavobacterium, Capnocytophaga, Corynebacterium, JGI 0000069-P22, Gracilibacteria, Luteimonas, Lautropia, and Absconditabacteriales SR1 were more abundant in cats fed the dry diet. Although most health indices were not different between treatment groups, cats fed the dry diet had higher levels of health-associated genera (Capnocytophaga and Corynebacterium) and lower levels of disease-associated genera (Filifactor, Tannerella, and Fretibacterium). The lower calculus scores and microbial shifts suggest oral health benefits of feeding dry diets, but more research is necessary to understand feline oral microbiota populations and how they contribute to biofilm formation, calculus and plaque buildup, and oral disease in cats.

  PublisherOA PDFDOI

• The Safety of FeedKind Pet® (Methylococcus capsulatus, Bath) as a Cultured Protein Source in the Diet of Adult Dogs and Its Effect on Feed Digestibility, Fecal Microbiome, and Health Status

  Animals · 2025-07-04

  articleOpen access

  Thirty-two healthy adult dogs (16 males and 16 females) were fed control kibble diets for one month, followed by six months (Weeks 0 to 25) of diets containing either 0, 4, 6, or 8% cultured protein derived from Methylococcus capsulatus (FeedKind Pet®, FK), then they were fed control diets (0% FK) for a further two months (Weeks 25 to 34). The diets were isonitrogenous, isolipidic, and isocaloric and stage- and age-specific. The dogs were assessed for overall health, weight gain, and body condition score (BCS). Blood samples were collected 1 week prior to randomization, during acclimation, then in Weeks 5, 13, 25, 30, 32, and 34 for hematology, coagulation, and clinical chemistry; urine was collected according to the same time schedule for urinalysis. Feces were assessed for parasite load and presence of occult blood during Weeks 5, 9, 13, 17, 21, and 25. Fecal samples were collected during acclimation and Weeks 25 and 34 for fecal microbiome analysis and in Week 25 for apparent total gastrointestinal tract digestibility (ATTD). All dogs maintained a healthy weight and BCS throughout the study. Hematology parameters were within normal limits at the end of each phase of the study. With the exception of a decrease in serum phosphorus level and in urine pH in all groups at the end of the study, urine and serum chemistry results were within normal limits at the end of each phase. ATTD values for organic matter, protein, and energy exceeded 80%, whilst digestibility values for copper were around 20%. The fecal microbiome was dominated by Firmicutes. Alpha diversity increased during the safety phase before returning to baseline levels during the washout phase. The dominant genera in all groups were Megamonas, Peptoclostridium, Turicibacter, Catenibacterium, Fusobacterium, Romboutsia, and Blautia. The study has shown that the inclusion of cultured protein at up to 8% of the total diet of adult dogs can provide sufficient nutrition and is safe with no long-term effects on a range of health parameters.

  PublisherOA PDFDOI

• Evaluation of Bacillus subtilis ATCC PTA-122264 on the fecal characteristics and microbiota of healthy adult dogs subjected to an abrupt diet change

  Frontiers in Veterinary Science · 2025-07-17 · 1 citations

  articleOpen accessSenior author

  Abrupt dietary transitions are common in pets, but can lead to digestive disturbances, altered gut microbiota composition, and impaired intestinal integrity. The consumption of live microorganisms may have potential to mitigate these effects by stabilizing the gut microbiota and enhancing intestinal functionality. The current study aimed to evaluate the effects of Bacillus subtilis ATCC PTA-122264 supplementation on fecal characteristics, microbiota composition, and dysbiosis index of dogs undergoing an abrupt dietary change. Twelve healthy adult spayed female beagle dogs (6.0 ± 1.14 yr; 8.7 ± 0.91 kg body weight) were used in a replicated 3 × 3 Latin square design. In each experimental period, dogs were allotted to one of three treatments and fed a high-fiber kibble diet for 28 d: (1) 250 mg/d of maltodextrin (control), (2) 1 × 10 9 colony-forming units (CFU)/d of B. subtilis , or (3) 5 × 10 9 CFU/d of B. subtilis . All dogs were then abruptly transitioned to a high-protein, high-fat canned diet and fed for 14 d. Fresh fecal samples were collected before (d 0) and 2, 6, 10, and 14 d after the diet change for fecal scoring, pH, dry matter (DM) content, and microbiota analysis. Data were statistically analyzed to identify differences due to treatment, time, and treatment*time interactions, with p < 0.05 accepted as being significant. Diet change did not impact fecal pH or scores but reduced fecal DM percentage and bacterial alpha diversity measures. Bacterial beta diversity analysis revealed a distinct shift in the microbial community following the diet transition. Diet change reduced ( p < 0.05) the abundances of short-chain fatty acid (SCFA)-producing bacteria and increased ( p < 0.05) the relative abundance of potentially pathogenic bacteria, resulting in an elevated ( p < 0.05) dysbiosis index. B. subtilis supplementation did not attenuate the microbial shifts caused by the diet transition. These findings confirm that an abrupt diet change significantly impacts some stool characteristics and fecal microbiota populations of dogs. Further investigation of Bacillus spp. strains and dosages is required to determine the potential benefits that they may provide during dietary transition.

  PublisherDOI

• 310 Apparent total tract nutrient digestibility of raw, minimally processed, and retorted dog foods and their effects on fecal characteristics, metabolites, and microbiota of healthy adult dogs.

  Journal of Animal Science · 2025-10-01

  articleOpen accessSenior author

  Abstract Previous research has demonstrated that pet food formats differ in their digestibility and impact on gastrointestinal health measures. However, these diets often vary in macronutrient concentrations and ingredient compositions, making it challenging to attribute differences. Therefore, the objectives of this study were to determine how diets of different formats formulated to similar nutrient targets using similar ingredients may affect the apparent total tract macronutrient digestibility (ATTD) and the gastrointestinal transit time (GTT) and fecal characteristics, metabolites, and microbiota of healthy dogs. Ten spayed female adult beagles (age = 6.10±1.20 yr) were used in a replicated 5x5 Latin square design to test the following diet formats: retorted (RT), minimally processed [sous vide (SV), steamed (ST)], and raw [high-pressure processed (HPP), freeze-dried (FD)]. The study comprised five 26-d periods, including a 7-d diet transition phase, 14-d treatment phase, and 5-d fecal collection. All feces excreted during the collection phase were pooled, dried, ground, and analyzed for dry matter (DM), organic matter (OM), crude protein, total lipid content, and gross energy. On the first day of fecal collections, one fresh fecal sample was collected to measure pH, DM content, fermentative metabolite concentrations, and microbiota composition. The following day, dogs were given a dye with their meal, feces were evaluated, and GTT was calculated. Data were analyzed by Mixed Models using SAS 9.4, with P < 0.05 being statistically significant. Fecal scores, pH, DM%, and GTT were not different among treatment groups. Dogs consuming the RT and FD diets had a higher (P < 0.05) as-is fecal output to DM intake ratio than dogs consuming the ST and HPP diets. The HPP and ST diets had higher (P < 0.05) DM and OM ATTD than the RT, FD, and SV (ST not different) diets. All diets had greater (P < 0.05) crude protein ATTD than the RT diet and higher (P < 0.05) fat ATTD than the FD diet. Energy ATTD was higher (P < 0.05) in the ST, HPP, and SV diets than in the FD and RT (SV not different) diets. Fecal acetate and butyrate were higher (P < 0.05) in dogs consuming the RT diet than the ST and SV (butyrate only) diets. Fecal isobutyrate, isovalerate, total BCFA, indole, and ammonia were higher (P < 0.05) in dogs consuming the RT diet than all other diets (ST not different for indole and ammonia). Alpha and beta diversity measures were not impacted, but diet altered the relative abundances of 3 bacterial phyla and 18 bacterial genera (P < 0.05). In summary, processing method influenced nutrient digestibility and the fecal metabolites and microbiota of healthy adult dogs. Further research is needed to evaluate additional factors such as packaging size, ingredient and macronutrient inclusion levels, different processing parameters, and other pet food formats.

  PublisherOA PDFDOI

• In vitro fermentation characteristics of dietary fibers using fecal inocula from dogs fed a canned diet and treated with metronidazole

  Frontiers in Veterinary Science · 2025-10-29 · 1 citations

  articleOpen accessSenior authorCorresponding

  Introduction Metronidazole is a potent antibiotic often prescribed to treat gastrointestinal enteropathies; however, it is known to induce loose stools, negatively alter the fecal microbiome, and affect fecal metabolite production. Dietary intervention may aid in post-antibiotic recovery; however, little research has been conducted on the potential of fiber utilization for microbial recovery in canines. Methods Using an in vitro fermentation assay, the objective of this study is to investigate the fermentation characteristics of dietary fibers using fecal inocula from dogs treated with metronidazole. Four healthy male beagles (age = 1.62 ± 0.02 year) were fed a commercial canned diet for 2 weeks, then administered metronidazole (20 mg/kg BW BID) for 2 weeks. Fresh fecal samples were collected at weeks 2 (before antibiotic treatment; ABX−) and 4 (after antibiotic treatment; ABX+), stabilized in a 20% glycerol solution, and then frozen. On the day of in vitro fermentation, feces from each time point were thawed and used to inoculate the tubes. At baseline and after 6, 12, and 18 h of fermentation, pH, short-chain fatty acids (SCFA), and microbiota were measured. Blank-corrected changes from the baseline data were analyzed using repeated measures and the MIXED procedure in SAS 9.4, with significance set at a p value <0.05. Results Pectin fermentation reduced ( p < 0.001) pH and increased ( p < 0.001) SCFA over time, but the responses were lower ( p < 0.001) in ABX+ than in ABX−. Beet pulp fermentation also reduced ( p < 0.001) pH and increased ( p < 0.001) SCFA over time. The pH change was small between inoculum sources, but SCFA were different ( p < 0.001) between ABX+ and ABX−. Chicory pulp fermentation reduced ( p < 0.001) pH over time, with greater ( p < 0.01) reductions in ABX+ than in ABX−. Chicory pulp fermentation increased SCFA but had different patterns depending on the inoculum source. Metronidazole altered microbiota populations by reducing bacterial alpha diversity ( p < 0.001). Analysis of bacterial beta diversity revealed separate clusters in dogs based on metronidazole administration. Beta diversity analysis also showed that tubes containing chicory pulp clustered separately from those containing other fibers. The relative abundance of over 50 bacterial genera differed ( p < 0.05) among the inoculum sources. Discussion In summary, interesting fermentation patterns were observed in response to varying fiber sources, allowing for improved insights into their potential abilities in antibiotic-treated dogs.

  PublisherOA PDFDOI

• Safety, efficacy, gastrointestinal tolerance, and digestibility of brewed chicken protein in healthy adult dogs

  Frontiers in Veterinary Science · 2025-07-07 · 2 citations

  articleOpen accessSenior authorCorresponding

  Introduction Producing enough protein continues to be a challenge, but alternatives may provide economic and ecological relief. Sufficient testing is necessary to confirm safety and evaluate nutritional value. Our objective was to evaluate the safety, efficacy, gastrointestinal tolerance, and apparent total tract digestibility (ATTD) of brewed chicken protein (BCP; Saccharomyces cerevisiae expressing a chicken protein). Methods Thirty-two healthy adult dogs (BW = 9.68 ± 1.18 kg; age = 4.16 ± 1.85 yr) were used in a completely randomized design ( n = 8/treatment). After a 2-wk acclimation phase, baseline measurements were collected and dogs were allotted to the following treatments and fed for 26 wk: control diet (0% BCP; Control), 15% BCP (Low), 30% BCP (Medium), or 40% BCP (High). Palatability was assessed by comparing dry diets coated with 0% (control) vs. 1% BCP in 20 adult dogs. Data were analyzed using the Mixed Models procedure of SAS 9.4, with p < 0.05 being significant and trends accepted at p < 0.10. Results Consumption of BCP did not affect food intake, BW, physical parameters, serum chemistry, hematology, and urinalysis. The dry matter, organic matter, and crude protein ATTD were greater ( p < 0.05) for High, while the fat ATTD was greater ( p < 0.05) for Control. Fecal output was lower ( p < 0.0001) and fecal dry matter was lower ( p < 0.001) for dogs fed High. Fecal acetate concentrations were lower ( p < 0.05) and propionate concentrations tended to be higher ( p = 0.06) in dogs fed BCP. Fecal isobutyrate, isovalerate, indole, total phenol and indole, and ammonia concentrations were lower ( p < 0.001) and fecal valerate concentrations were higher ( p < 0.0001) in dogs fed BCP. Fecal bacterial alpha diversity was lower ( p < 0.05) in dogs fed BCP. For beta diversity, dogs fed Control were different than those fed BCP. Over 20 fecal bacterial genera were affected by BCP consumption. Palatability of BCP was high ( p < 0.05; 2.93:1 consumption ratio). Conclusion These results indicate that the BCP ingredient tested is an effective source of protein that is safe for use in adult dog foods at an inclusion level of up to 40%. No detrimental effects were observed, and notable changes to nutrient digestibility and fecal characteristics, metabolites, and microbiota populations suggest potential benefits on gastrointestinal health.

  PublisherOA PDFDOI

• PSIX-12 In Vitro fermentation characteristics of acacia fiber using feline fecal inoculum.

  Journal of Animal Science · 2025-10-01

  articleOpen accessSenior author

  Abstract Acacia fiber is a soluble fiber often used as a processing aid in pet foods. The objective of this experiment was to evaluate the fermentation characteristics of acacia fiber, inulin, pectin (positive control), and cellulose (negative control) using an in vitro fermentation system and feline fecal inoculum. Triplicate samples of each fiber were fermented for 0, 6, 12, and 18 h, with short-chain fatty acids (SCFA), pH, and microbiota measured at each time point. Blank-corrected data were analyzed using PROC GLIMMIX of SAS, with significance set at P≤0.05. Significant (P< 0.01) fiber*time interactions were observed for pH change, gas and SCFA production, and microbiota populations. Pectin and inulin had greater (P< 0.01) gas production than acacia fiber and cellulose. Inulin had the greatest pH reduction, followed by pectin, both of which had greater pH reductions (P< 0.01) than acacia fiber and cellulose. Acacia fiber had a small reduction in pH, being lower than cellulose after 12 h. Total SCFA production, including acetate, propionate, and butyrate, was higher (P< 0.01) in pectin and inulin than acacia fiber and cellulose. However, acacia fiber had greater (P< 0.01) total SCFA, acetate, and propionate production than cellulose after 12 h. Bacterial alpha diversity metrics increased (P< 0.01) during acacia fiber fermentation and decreased (P< 0.01) during inulin and pectin fermentation. Bacterial beta diversity shifted over time and showed separate clustering of bacterial communities among the different fiber substrates evaluated. The relative abundances of predominant (% sequences > 1%) bacterial genera were affected by significant fiber*time interactions. Specifically, acacia fiber had a greater (P< 0.01) increase in Bacteroides, Blautia, and Faecalibacterium than other fibers. Inulin had a greater (P< 0.01) increase in Collinsella, Prevotella, Megamonas, Holdemanella, Blautia and Faecalibacterium, whereas pectin had a greater (P< 0.01) increase of Bifidobacterium, Lactobacillus, Phascolarctobacterium, and Succinivibrio. These results suggest that acacia fiber is moderately fermentable, resulting in low gas and SCFA production, greater bacterial diversity, and microbiota shifts. Although positive responses were observed in vitro, research in live animals is necessary to confirm potential benefits in cats.

  PublisherOA PDFDOI

Recent grants

• Targeted Drug Delivery to Adipose Tissue Macrophages in Obesity

  NIH · $2.1M · 2016–2022

Frequent coauthors

• G. C. Fahey

  University of Illinois Urbana-Champaign

  108 shared

• Patrícia M Oba

  University of Illinois Urbana-Champaign

  76 shared

• Brittany M. Vester

  56 shared

• Hannah D. Holscher

  51 shared

• María R C de Godoy

  University of Illinois Urbana-Champaign

  47 shared

• C.M. Parsons

  University of Illinois Urbana-Champaign

  36 shared

• Brittany M. Vester Boler

  36 shared

• Tzu-Wen Cross

  Purdue University West Lafayette

  34 shared

Labs

• Comparative Nutrition and NutrigenomicsPI