(P32-17-26) The Effects of a Dietary Pulse Intervention on Markers of Gut Integrity and Health

Objectives: To assess whether consumption of a nutritionally balanced diet containing low or high doses of dietary pulses for 1 week leads to changes in biomarkers of intestinal health and integrity.

Methods: A randomized controlled cross-over trial with washout periods was conducted at the USDA Western Human Nutrition Research Center. Healthy adults (n =18) completed 3 isocaloric dietary interventions (no pulse =0 g/d, low pulse =30g/d, high pulse =205g/d) for 6 days of home consumption with a study visit on day 7 to obtain fasting blood and return a fecal collection within 24h. Plasma biomarkers of inflammation and intestinal health were measured by ELISA: plasma sCD14 and IL-6. Ongoing efforts examine lipopolysaccharide binding protein (LBP), and fecal secretory IgA (sIgA), Calprotectin, and Lipocalin-2 (Lcn-2). Statistical analyses include repeated measure ANOVA with post hoc tests.

Results: Participants (5 M/ 13 F) had mean age of 29 years and weight of 67.9 kg, with BMI of 23.0 kg/m². Food frequency questionnaires showed a mean estimated daily intake of 16.4 grams dietary fiber and 3.7 servings of F&V. Reported bean intake frequency was: 5 participants consumed beans < 1x/wk, 4 at 1x/wk, 5 at 2-3x/wk, and 4 at 4-6x/wk.

A significant effect of dietary pulse consumption on plasma CD14 concentration (p =0.02) was seen, implying diet influenced intestinal permeability. Mean CD14 concentrations were variable at 1.50 ± 0.22μg/mL for control, 1.19 ± 0.44μg/mL for low, and 1.44 ± 0.34μg/mL for high pulse diet. Post-hoc pairwise comparisons using Tukey’s HSD showed no significant differences between diet conditions (high vs. low: p =0.14; high vs. control: p =0.66; low vs control: p =0.07). No significant effect of diet was found on IL-6 concentration (p =0.79). Mean IL-6 concentrations were 0.93 ± 0.56pg/mL for control, 0.93 ± 0.68pg/mL for low, and 0.98 ± 0.78pg/mL for high pulse diet. Pairwise comparisons were nonsignificant.

Conclusions: Dietary pulse intake may influence gut permeability, as reported by plasma CD14 concentrations. Conversely, the duration of pulse intake in this study may not be sufficient to cause significant changes in systemic inflammation as reported by plasma IL-6 in individuals of middle age with normal body weights.

Funding Sources: USDA NIFA CA-D-NTR-6316-H, USDA ARS Pulse Crop Health Initiative