Gelesis' Oral superabsorbent hydrogels (OSH) are crosslinked cellulose-based materials that expand upon hydration in the gastrointestinal tract and are engineered to mimic the mechanical properties of masticated vegetables. One OSH prototype, denoted Gel-B, was tested in both preventative and treatment settings in murine models of diet-induced obesity. Gel-B administration blunted weight gain, reversed gut atrophy, improved metabolic parameters (glucose and insulin tolerance tests; GTT and ITT) and restored barrier function. Here, we investigated the functional role of the gut microbiome to partially explain these protective metabolic effects.

Metabolic disease was induced in both Donor (n=24) and Recipient (n=24) C57BL6/J mice via consumption of a high fat and high cholesterol/carbohydrate (HFHCC) diet for weeks (wks) . Donor mice continued on HFHCC or were treated with HFHCC+Gel-B (2 or 4%) for an additional 6 wks. After 2 wks treatment, Donor fecal samples were processed every other day for intestinal microbiota transplantation (IMT) . Recipient mice continued HFHCC and received IMT derived from either HFHCC or Gel-B (2 or 4%) treated Donors via gavage every other day for 4 wks.

At 4 wks, the HFHCC-corrected % body weight difference in Recipients was -10.8% and -9.6% for the 2% Gel-B-derived IMT (p=0.02) , and 4% Gel-B-derived IMT (p= 0.02) respectively. Glucose excursions, AUC 0-2h from GTT, were significantly reduced in both Recipient groups (p=0.for both 2% and 4% Gel-B-derived IMT) . The AUC 0-2h from ITT were significantly increased in the 4% Gel-B-derived IMT Recipients (p=0.04) and trended for the 2% Gel-B-derived IMT group (p=0.13) .

The present study demonstrates for the first time that IMT from Gel-B treated Donors confers beneficial metabolic effects in HFHCC treated mice. Future experiments will define Gel-B associated microbiota and examine engraftment and durability of IMT.


A.Silvestri: None. A.Gil-gomez: None. E.Chiquette: Employee; Gelesis. C.Demitri: Stock/Shareholder; Gelesis. B.W.Jones: Employee; Gelesis. A.Sannino: None. M.Rescigno: Research Support; Gelesis.

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