We have included for your reference the brands that have been used in the publications identified on this site.
 

There are a couple of nucleotide-based food supplements that have clinical research:

IntestAid^®IB – Nucleotide Nutrition Limited (formerly Pro Bio Healthcare), UK. www.nucleotidenutrition.com

Dancey et al. Nucleotide supplementation: a randomised double blind placebo controlled trial pf IntestAid IB in people with irritable bowel syndrome. Nutrition Journal 2006, 5:16.

 
NuCell^®IM – Nucleotide Nutrition Limited (Pro Bio Healthcare), UK. www.nucleotidenutrition.com

Mc Naughton L, Bentley D, Koeppel P. The effects of a nucleotide supplement on the immune and metabolic response to short term, high intensity exercise performance in trained male subjects. J Sports Med Phys Fitness. 2007 Mar;47(1):112-8.

Mc Naughton L, Bentley DJ, Koeppel P. The effects of a nucleotide supplement on salivary IgA and cortisol after moderate endurance exercise. J Sports Med Phys Fitness. 2006 Mar; 46(1):84-9.

SMA formula – Wyeth, www.smanutrition.co.uk

Carver JD, Pimentel B, Cox WI, Barness LA. Dietary nucleotide effects upon immune function in infants. Pediatrics 1991; 88: 359-63.

Hawkes JS, Gibson RA, Roberton D, Makrides M. Effect of dietary nucleotide supplementation on growth and immune function in term infants: a randomized controlled trial. Eur J Clin Nutr. 2006 Feb;60(2):254-64Vasquez-Garibay 2004.

 
Similac – Abbott laboratories Inc, Illinois, USA.  www.abbott.com

Merolla R; Gruppo Pediatri Sperimentatori. Evaluation of the effects of a nucleotide-enriched formula on the incidence of diarrhea. Italian multicentre national study. Minerva Pediatr. 2000; 52(12):699-711 (Italian).

Pickering LK, Granoff DM, Erickson JR, Masor ML, Cordle CT, Schaller JP, et al. Modulation of the immune system by human milk and infant formula containing nucleotides. Pediatrics 1998; 101: 242-9.

Several enteral feeds containing so-called immunomodulators (usually arginine, omega-3 fatty acids and nucleotides) are available for clinical use e.g. IMPACT.

IMPACT – Novartis Medical Nutrition. www.novartis.com

Beale, R. J., Bryg, D. J. and Bihari, D. J. (1999). Immunonutrition in the critically ill: a systematic review of clinical outcome. Critical Care Medicine 27:12, 2799-805.

Bower RH, Cerra FB, Bershadsky B, Licari JJ, Hoyt DB, Jensen GL, Van Buren CT, Rothkopf MM, Daly JM, Adelsberg BR. Early enteral administration of a formula (Impact) supplemented with arginine, nucleotides, and fish oil in intensive care unit patients: results of a multicenter, prospective, randomized, clinical trial. Crit Care Med. 1995; 23(3):436-49.