The role of enteral fat as a modulator of body composition after small bowel resection

Abstract

Background: After massive small bowel resection (SBR), a postoperative diet high in fat is associated with enhanced villus growth. The purpose of this study was to further elucidate the quantity and composition of enteral fat in structural and metabolic changes after SBR.

Methods: C57/Bl6 mice underwent a 50% proximal SBR. Mice were then randomized to receive a low-fat diet (12% kcal fat), medium-fat diet (44% kcal fat), or high-fat diet (HFD; 71% kcal fat) ad libitum. In a separate experiment, mice underwent 50% proximal SBR and then were randomized to liquid diets of 42% kcal of fat in which the fat was composed of menhaden oil, milk fat, or olive oil. After 2 weeks, mice underwent body composition analysis and the small intestine was harvested.

Results: Mice that ingested the greatest amount of enteral fat (HFD) had the greatest percent lean mass. When the effects of the different kinds of enteral fat were analyzed, mice that consumed menhaden oil had the greatest percent lean mass with the greatest overall retention of preoperative weight.

Conclusion: These findings suggest that enteral fat enriched in omega-3 fatty acids may offer clinically relevant metabolic advantages for patients with short gut syndrome.

Figure 1

Percentage of preoperative weight of mice on postoperative days 7-14 based on preoperative weight. LFD = Low Fat Diet, MFD = Medium Fat Diet, HFD = High Fat Diet. * p < 0.05 between LFD and HFD, ^ p < 0.05 between HFD and MFD, # p < 0.05 between MFD and LFD

Figure 2

Percent lean mass measured at postoperative day 14. LFD = Low Fat Diet, MFD = Medium Fat Diet, HFD = High Fat Diet. NS = No Significance, ** p < 0.005

Figure 3

Total kilocalories of food consumed per day. LFD = Low Fat Diet, MFD = Medium Fat Diet, HFD = High Fat Diet. * p < 0.05

Figure 4

Percent increase in villus height from intraoperative measurement to postoperative day 14. LFD = Low Fat Diet, MFD = Medium Fat Diet, HFD = High Fat Diet. * p < 0.05, ** p < 0.005

Figure 5

Fat (A) and carbohydrate (B) related mRNA expression of diglyceride acyltransferase (DGAT), microsomal triglyceride transporter protein (MTTP), CD36, apolipoprotein B (ApoB), glucose transporter 2 (GLUT2) and sodium glucose linked transporter (SGLT1) as determined by RT-PCR. β–Actin was used as the endogenous control, and whole bowel was used as a calibrator. LFD = Low Fat Diet, MFD = Medium Fat Diet, HFD = High Fat Diet. * p < 0.05, ** p < 0.005

Figure 6

Percentage of preoperative weight mice on postoperative days 7-14 based on preoperative weight. MO = Menhaden Oil Diet, MF = Milk Fat Diet, OO = Olive Oil Diet. * p < 0.05 between MO and MF, ^ p < 0.05 between MF and OO, # p < 0.05 between OO and MO

Figure 7

Percent lean mass measured at postoperative day 14. MO = Menhaden Oil Diet, MF = Milk Fat Diet, OO = Olive Oil Diet. ** p < 0.005

Figure 8

Total kilocalories of food consumed per day. MO = Menhaden Oil Diet, MF = Milk Fat Diet, OO = Olive Oil Diet. NS = No Significance, * p < 0.05

Figure 9

Fat related mRNA expression of microsomal triglyceride transporter protein (MTTP), CD36, and apolipoprotein B (ApoB) as determined by RT-PCR. β–Actin was used as the endogenous control, and whole bowel was used as a calibrator. MO = Menhaden Oil Diet, MF = Milk Fat Diet, OO = Olive Oil Diet. * p < 0.05, ** p < 0.005