# Nutritional Support for Liver Diseases
## 2 Nutritional Support for Liver Diseases
### Liver Transplantation
#### 2.4.1 Nutritional Support before Liver Transplantation  
Patients being prepared for surgery should maintain a diet dedicated to their current clinical condition. Depending on whether the patient has features of encephalopathy, the supply of protein in the diet should be modified. The goal of nutritional therapy before transplantation is to provide a diet with an optimal supply of energy and protein to counteract the development of malnutrition and to supplement the identified deficiencies of nutrients [145]. In hepatological patients, special attention should be paid to the possibility of deficiencies in fat-soluble vitamins, B vitamins, zinc, magnesium, and antioxidant micronutrients (selenium, vitamin E, and vitamin C) [150]. The recommendations in the preoperative and postoperative periods are presented in Table 2. \begin{table}
\begin{tabular}{c c} \hline \hline
**Symptoms/Patient’s Condition** & **Recommendation** \\ \hline \multicolumn{2}{c}{PREOPERATIVE PERIOD} \\ \hline Current condition of the patient & Diet adapted to the patient’s condition [145]; \\  & optimal supply of energy: 30–35 kcal/kg BW/day [151]; \\  & obese patient: EN or PN 25 kcal/kg IBW/day [151] \\  & optimal supply of protein:1.2–1.5 g/kg) [151]; obese \\  & patients: 2.0–2.5 g/kg IBW/day [151]; \\  & optimal supply of fat-soluble vitamins, B vitamins, zinc, \\  & magnesium, antioxidants (selenium, vit E, and vit C) [150]; \\ \hline Hepatic encephalopathy & Modified protein intake [145]; \\ \hline Malnourished patients (BMI \textless{} 18.5\) kg/m\({}^{2}\); & Oral nutritional supplements (ONS) for 7 days before \\  & weight loss \textgreater{} 10–15\% within 6 months; \\  & serum albumin \textless{} 30 g/L) \\ \hline Severely malnourished patients (more than \\  & 10\% WL) & Surgery postponed by 2 weeks [152]; \\  & Improving nutritional status [152]; \\ \hline Infectious complications risk & Formulas enriched with arginine, omega-3 fatty acids, \\  & nucleotides [153]; \\ \hline Preoperative fasting & Shortening fasting period [151]; \\  & 6 h for solid food and 2 h for fluid before surgery [151]; \\ \hline Postoperative insulin resistance & Clear carbohydrate fluid 2 h before surgery [151; 154]; \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Recommendation in the pre-operative and postoperative period. Patients at risk of malnutrition and meeting the following criteria: BMI! 18.5 kg/m\({}^{2}\), weight loss! 10-15% within 6 months, and serum albumin! 30 g/L in the absence of liver or renal dysfunction are recommended to take oral nutritional supplements (ONS) for 7 days before the scheduled surgery date. In severely malnourished patients (loss of more than 10% WL), it is recommended to postpone surgery for 2 weeks. During this time, care should be taken to improve the patient's nutritional status and increase the patient's body weight [152]. It is recommended that patients prepared for liver transplantation should follow the guidelines of the Enhanced Recovery After Surgery (ERAS) protocol [147; 151]. The guidelines indicate that in the preoperative period, the caloric content of the diet should be 30-35 kcal/kg/d, and the protein supply should be at the level of 1.5 g/kg/d, following the standard nutrition scheme (Evidence level: high; Grade of recommendation: strong) [151]. The effect of BCAA supplementation in patients undergoing liver transplantation was evaluated in the studies of [PERSON] et al. [157] and [PERSON] et al. [158]. The studies indicated a significant improvement in the treatment of sepsis [157] and a reduction in bacteremia in the postoperative period [159]. It should also be noted that the current rules of ERAS protocol do not indicate the need to include such preparations in patients [147]. There is evidence to include probiotics before or on the day of liver transplantation. Depending on the study, the duration of supplementation was different, and a variable number of strains was also used (Evidence level: high; Grade of recommendation: weak) [151; 159; 160]. The meta-analysis conducted by [PERSON] et al.