It is a well known, but no less extraordinary fact, that the energy in all nutrients has at some time been stored in photons that have travelled from the sun to the earth. Of course, the date of this travel varies greatly. It ranges from recent photosynthesis of foods in plants to fish oils that may have been locked in food chains for centuries. It is inevitable that nutritional research will try to move away from our dependence on past sunlight. This will require research into two components; a non-solar source of energy; and a novel energy transduction pathway into organic nutrients. The generation of non-solar energy is beyond the scope of nutritional research and it likely to come from either nuclear fusion or the heat in the centre of the earth. Trapping this energy into nutrition is the exciting new area of the future. Currently, photosynthesis by plants and bacteria provides the only method of trapping radiant energy into organic materials. Development of a new form of nutritional biochemistry that undertakes this research is likely to neutralise mechanisms currently employed by plants in addition to undertaking completely novel energy transduction pathways. This revolutionary area of research has hardly begun.

Nutrition and information transfer

The effect of nutrition on the transfer and storage of information is also a developing field. Already the mechanisms underlying the ability of nutrients to alter gene expression are under active scrutiny.

Considerable work in the last few years has examined nutrient interactions both on promoter based regulation of gene expression and on epigenetic mechanisms. In particular, the ability of nutrients to alter chromosomal structure¹ indicates the power by which nutrition can alter the immune system, particularly when the genes regulated have immune potential. By 2050 many of the pathways by which nutrients interact with chromosomes, DNA, transcription and translation will have been fully elucidated. This will result in targeted mechanisms to modify the expression of genes upregulated through nutritional therapies. The observation that enteral feeds induce remission in children with Crohn’s disease² already points to the potential of nutritional therapies in immune based diseases.

While researching this area will be interesting, it cannot be thought of as a new way of thinking from the way we work at present. New forms of information storage and transfer within biological systems are likely to be developed within the next fifty years. These can be categorised as information transfer and storage within cells, between cells of a single organism and between organisms. The information exchange between organisms and the effect of nutrition upon them is likely to focus on bacterial eukaryotic interactions in the intestine. Already we know that nutritional effects on laboratory animals are influenced by bacterial flora³. Germ-free mice given the same nutritional intake as colonised mice exhibit remarkable differences in adiposity. The authors suggest that variations in bacterial flora may directly affect the tendency to gain weight in different individuals. The question that remains to be answered over the next fifty years is to what extent do nutrients modulate the signals that bacteria release and are received by the body. At present, we only have a hazy idea of what these signals might be. It is therefore difficult to predict exactly how this research will move forward; but it is already possible to discern three points by which nutrition can affect these processes:

• the effect of nutrients on the bacteria to signal to humans
• their modification within the space of the intestine of the signals themselves (one can imagine that the molecular entities released could combine in intriguing ways with nutrients in the intestine)
• the modifications in receptor mechanisms that receive these signals

Cell-cell interactions are central to the immune system. These comprise both direct contact between cells, and signals released between them. We have already alluded to the regulation of genes by nutrients and this will become manifest on new cell-cell signalling pathways not yet discovered.

Nutrients and immune function

The effect of nutrients on the immune system on the transfer of information and storage of information within cells is possibly the most interesting area for the future. We currently understand information being transcribed and translated from nucleic acid to protein. More recently, information within the chromosome has been elucidated. The structure of histone and the chemical modifications of these important proteins are now being understood as a second form of information storage. The ability of nutrients to affect these has implications on the effects of nutrition and cancer as well as nutrition and the immune system. Other mechanisms of storage of information included concepts that are not readily understood today and these involve the three dimensional structures of membranes in the cell, sugar macromolecules, and variations in cellular charge. We are not capable yet of understanding how a membrane three dimensional structure can store information but there is no doubt of the ability of the membrane to support and influence biological systems. Furthermore, it is easy to comprehend that once this has been elucidated, that nutrients could alter the three dimensional structures of membranes both by varying the fluidity of the lipid component of the membranes and by inserting or removing protein associated with it. It is likely that the immune system, in particular, uses techniques such as this to maintain information. Much of the information that is required by the immune system is not required by other cells and therefore a mechanism by which cell specific information is stored and transmitted is likely to have evolved.

Finally, a little understood mechanism of information storage is the deposition of sugar moieties on proteins on different parts of the cell. It is already known that T cell activation alters the glycosylation of critical proteins on the surface of the lymphocyte. The mechanisms for these have not yet been shown to be nutrient dependent but are likely to be so. Furthermore, we do not understand why this phenomenon occurs and what information it imparts, but it seems likely that this is a small example of a much wider area which will require elucidation.

In summary, the future of nutritional research appears enormous. There is not only the question of new forms of nutrient energy but other ways by which nutrients can alter the transmission and storage of information within cells relevant to the immune system.

References

1. Sanderson IR. Short chain fatty acid regulation of signaling genes expressed by the intestinal epithelium. J Nutr. 2004;134:2450S-4.
2. Sanderson IR, Croft NM. The anti-inflammatory effects of enteral nutrition. J Parenter Enteral Nutr. 2005;29(4 Suppl):S134-8.
3. Backhed F, Ding H, Wang T, et al. The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci U S A. 2004;101:15718-23.